Everything about practicing the Course could be described as moving "backwards". Accustomed to how the ego operates always "forwards" this can at first seem counter-intuitive and a difficult "direction" for the mind to operate in.
Purification and correction are entirely geared towards a backwards motion, such as retracing your steps, seeking inward rather than outward, undoing, reversing, collapsing, deflating ego, re-winding time, digging deeper to find the true inner cause, looking "behind", getting to the core of oneself, going within, taking attention away from illusions, becoming whole, acknowledging what already is, accepting what is already true, receiving what is already given, lifting away layers of false belief, recognizing things for how they are, taking back projections, claiming responsibility for yourself, re-owning yourself, coming back to center, un-ravelling, seeking back through time to when beliefs were formed, reversing the effects of sin, cancelling, deleting, removing, restoring to a former state, moving backward to before any sense of something happening, returning to innocence, becoming aware of love which is already present, listening, receiving, accepting, allowing, reversing sickness and death, resurrection etc.
Notice that all of these procedures take you from being externally focused to focusing within, in the direction of yourself. The truth is inside of you. All of these actions return you to yourself.
Now, the ego is the total opposite of this in every way. The ego wants to always add something, increase denial, hide stuff behind new layers of illusions, implement things, find success, seek outside yourself, lose yourself, forget who you are, move away from yourself and God, project, attack, point a finger of blame away from you, destroy others, fight with an opposing will, acquire, get, consume the external (food etc), implement magical solutions which undo nothing, add lie upon lie, twist and distort things out of recognition, get rid of sin onto others, disassociate from yourself, believe that cause is outside of you, see yourself as an effect of the external, positioning yourself as a victim of something separate, pursuing wild goose chases and dead ends, running away from God, becoming alone and isolated, losing your mind and sanity, fragmentation, making others responsible for your existence, trying to get someone else to choose for you, trying to get someone else to love for you or to wake you up, going to sleep, living in ignorance, becoming unconscious, entering darkness, achieve, strive for goals, develop an image, accumulate and build stuff that never existed, fill the emptiness with idols, idol worship, seeking external salvation, believing that things outside you can save you and solve all problems, being sick as a result of an external cause, dying by someone else's hand, listening to the ego's counsel, making things worse, an eye for an eye, waging war, murder, etc.
Notice that all of these actions are in an outward direction, away from yourself. They are all designed to disconnect you from God and put distance between you and God and therefore between you and yourself. They take you away from yourself and place every attribute of yourself outside of you into someone else's hands.
The main difficulty I find is that having been in the ego mindset for such a long time, my mind has sort of become very used to or unconsciously has formed habits whereby the mind moves in a direction away from myself. It pursues the external and thinks in externalizing ways. It's like there's all these arrows pointing outward and it seems to make the mind "flow" in that direction automatically. Even normal "thinking" processes seem to head in the direction of the external and these are just accepted as automatic or "normal".
So then when we come to the Course, our mind is coming up against a set of truths and techniques which are all INWARD pointing, and basically flowing in totally the OPPOSITE direction to the ego's thought system. They all point towards God, towards your true self, towards what is inside of you already. Even just the simple idea that you need not seek to find love or teach love because that is what you are but that you need to REMOVE the obstacles you've built against it. We are not accustomed to REMOVING anything. We're accustomed to believing that we LACK God and therefore need to go seek for specialness and ADD it to ourselves in order to "become" loving or spiritual. That's totally the ego, KEEPING its belief in sin and hiding it and then pretending to try to find solutions to it externally, where solutions do not exist, and thus building layer upon layer of denial and failure. It's all the authority problem, believing we can add to or change God's creation into something better or more true.
So it's quite difficult to get the mind to even move in the direction of thinking inwards, thinking upwards, thinking IN REVERSE, or thinking towards what ALREADY EXISTS within you. To think in reverse means to go from where your mind is at to what came BEFORE it, rather than going from where your mind is at and proceeding forwards to some kind of next step. It seems alien. It seems unnatural at first. It seems to take steps that bring all of the illusion into question, all assumptions are undermined, and all beliefs have to be examined and exhumed and tossed out, all values are brought into question, every attachment has to be surrendered, all external structures are collapsed, and your whole life is brought into question. And that's not what the ego wants at all, and it's not how we're used to thinking. To question everything, to question sin and sickness and death. To assume nothing, and to believe nothing that even our body's senses are telling us. To travel backwards up the chain of causality to where we came from.
You are already as God created you, you are already love, you are already perfect, there is NOTHING you can add to God's creation or Kingdom other than to increase what is already in it, which is perfect joy and love and happiness. And you are already WHOLE, already complete, needing nothing, lacking nothing. All of this other stuff that you keep trying to deal with by ADDING or CHANGING layers of illusions, are ego solutions and ways of dealing with this, really attempts to hide it even more.
So like, something happens and your ego steps in with a reaction and says, oh my God, this thing is so externally real, it is really happening, and the future is going to suck, so I better do something about this. I know, I'm going to do this and that... and then comes up with a long list of reactions and plans and solutions which it is going to DO, to tackle what it itself made real, as though something really occurred. It creates this entire "chain of thought" or train of thought, which goes from "here" to way off in the distance down all kinds of twists and turns, taking you away from presence. We need to stop the train before it even leaves the station, get off it, and then look backwards down the tracks to where we CAME FROM and go in THAT direction, undoing, backtracking, reversing and returning, inwardly and upwardly BACK to the truth, BACK to the answer to end all questions, and BACK Home to God.
To think with Holy Spirit is to think BACKWARDS. This requires us to initially STOP and put the pause button on. Freeze-frame things. Freeze the entire scenario and just observe what it contains, from a big perspective. And then start to REVERSE the steps we have already taken, to backtrack, to look at our real hidden motives (secret sins/hates etc), and to UNDO layer upon layer of false beliefs and projections and stuff that we basically tried to ADD to ourselves already, that has led to us witnessing a falsely perceived situation. But this seems awkward and counter-intuitive - or at least counter-ego. It's therefore essentially all about letting go and letting God, relinquishing attachments, surrendering to what is already true, accepting God as God is, returning to yourself, and becoming EMPTY of all the stuff that you "added" to yourself to try to make yourself become something you are not - different to how God created you (and how you still are, buried under the ego lies).
To question... "has this even really happened" - that's a totally backwards step which brings into question any ASSUMPTION that the ego has made, and digs way deeper into what is happening than to react to it and try to fix it or attack it with Course quotes or to deny it with fake positivity or to build a spiritual ego to defend against it (and keep it). To stop and go backwards, to ask, is this even real? Why do I believe this? Where is my perception coming from? Why have I chosen this? How did I put this in place myself? Who am I really underneath this? Is this really true of me? Not ACCEPTING stuff into your mind.
As Jesus says, whatever you accept into your mind, it becomes real to you. The ego automatically is just accepting everything "into" the mind like a black hole sucking the life out of everything. We have to learn to stop that, to think in reverse, and to cancel the ego, to go within, to reverse our thinking processes and develop this new "inward direction" which flows away from illusions and towards the PRE-EXISTING truth and love within us, which is already there and is already perfect. To ACKNOWLEDGE what is already true and accept it, rather than trying to REPLACE it or cover it up or deny it with stuff we MAKE (invent/add) with the ego.
At first this kind of backwards thinking is not at all easy for the mind to do. It seems like the mind has become "wired" to think forwards with the ego, outwardly. But gradually over time as you "practice" this and go through this PURIFICATION process, digging out and releasing old pain, getting to the bottom of things, finding yourself, taking back your power, returning to responsibility, accessing the power of choice, accepting atonement, it becomes easier because there is less of your own ego-aligned will working against you.
It's like you're literally learning how to reverse the direction of flow of a river. The mind has become separated from Spirit and is flowing out all by itself, broadcasting its own ideas and trying to replace God's creation with something of its own. That needs to be totally reversed and undone. We need to go back within and reconnect with God and plug ourselves back into the service of Spirit. It takes time to break out of the unconscious habits of flowing outward with the ego.
And there is a paradox here. Funnily enough, the more you go within and withdraw your projections away from the external and get to the core love that's already in you, THEN that's when love starts to radiate out from you. You don't become loving by trying to give give give without receiving.
You must receive inwards first. It's more like, you become a light bulb, the switch goes on, and you simply stay CENTERED and rooted in your true self, in Spirit, and you RADIATE from there, staying in that center at all times, instead of going away from yourself or abandoning or losing yourself. To the ego giving is a loss of yourself. To Spirit, giving INCREASES and you not only keep/hold onto your inner real self but you also SHARE that and it extends out on its own. Love extends because of what it is, without your help.
So to be more loving, stop dwelling on the external or on trying to sacrifice yourself or martyr yourself. Return inward to access awareness of love's presence and then simply SHINE from within. This is how God creates, by shining and radiating and sharing and extending, remaining true to Himself and still complete and anchored within Himself. He does not lose Himself in the process. This is how the Kingdom is increased. This is what it means to be the light of the world. To shine from within rather than to lose yourself. To become an intensely bright light which goes out from within. You have to BE WITHIN first in order to do that, and stay there. This outward shining is CREATION, and it is the same thing as sharing and extending. It is how God created you to begin with. And in that light you have never stopped being God's innocent child.