The main ego reaction is that we perceive the Course's truth to be very highly truthful, powerful and authoritative. We start to set Jesus up as an authority over us. We get this sense of how the Course is 'right'and how we are 'wrong', because our ego is so accustomed to making right and wrong out of everything.
We put the Course up on a pedestal and worship it. And if you think you're not religious or prefer ACIM over Christianity or whatever, think again - your ego is quite prepared to be religious about the course, to worship its leader, to be subservient to its power and authority, and to use it as a way to amplify guilt by pointing out all the ways that you seem to be inferior and wrong in comparison to Jesus's truth.
We then take on all of these things which the Course says and all of these high concepts, and we build up this picture of attainability. We believe the Course is telling the truth but we use it to tell ourselves why WE are not being this truthful. We find ourselves guilty and shameful in the mirror reflection and this starts compelling us to 'become better' and 'match up' and 'be more spiritual' and 'have more mental discipline' and all these ego motivations that aim for this new lofty perfection.
Trouble is all of this takes us away from where we actually ARE right now, which is the ego's favorite trick to deny what you already are. And you just end up feeling like you can't do the Course properly and you're guilty and wrong and incapable, and you will try really hard and feel shitty about it because you just can't seem to do it or get it. Because your ego keeps using it to reinforce itself, to prove why you are not truthful and why you are not good enough and why you should put even more effort into people-pleasing Jesus's authority. And so you prostrate yourself at the feet of the Course and give power over you and end up feeling like a worthless idiot, riddled with fear and shame and not being Good enough for God.
What also happens here is that you then read things which are very high-level, like, in terms of the 'levels' it's stuff from level 3, 4, 5 - levels of higher self, levels of christ consciousness, which really are waaaaay outside the scope of where you are at right now. But this huge GAP between where you are AT and where it seems like you're supposed to BE, in comparison, just breeds guilt and loathing.
You start to believe that you believe the course, by trying to DENY what you really believe and trying to AVOID what you really feel and trying to NOT BE who you actually are. You try to become something else. This is your PERSONA, putting on a spiritual facade and trying to measure up to what you generally experience as a very highly advanced spiritual state that you barely comprehend. And the result of amplifying your persona is that you shove all kinds of shit into your 'shadow'/unconscious which comes back to attack you. So now you say what you're "supposed" to say, and you try to feel only what you're "supposed" to feel. And you modify your behavior. And you feel like a big fat failure.
This is because you're out of touch with what you are actually EXPERIENCING, you don't think it's OK to be where you're at, and you keep beating yourself up with or trying to FIT INTO what you THINK you SHOULD be like, or should be experiencing. The Course's goals seem so far beyond what you can experience that it leads you to bypass and to pretend and to become MORE out of touch with your inner power and strength and certainty than you probably were even before you started the dam thing!
This isn't the Course's fault. It's your ego's fault. Its the ego's interference and interpretation and conclusion-making that leads you into all this pressure to measure up, rather than making it ok to remain in-touch with where you are at, or even all the spiritual growth that you already had before you came to the Course. Maybe you need to kick some of the course to the kerb for now, or at least let go of trying to fit into shoes that are too big based on where you're at or what you're learning. Get back in touch with what's true for you right now and what you can realistically achieve, rather than trying to measure up to some standard that is so advanced it's barely conceivable.
Much of the course community is doing this at this time, and is rife with 'trying' to be spiritual, 'trying' to attain higher-levels of truth without actually experiencing it. Talking about it, spewing out quotes and statements about it, using it as 'pleasantries', making posters out of it, recalling quips about it like some kind of parrot, and generally going into all the intellectualizing about it, out of touch with FEELING, out of touch with EXPERIENCING. We all need to get ourselves back down to earth and in touch with what's going on with us, rather than what we're trying to become.