I once thought that unconditional love meant that I would unconditionally love one person. That is, that I would love them a lot. I thought that this 'big love' was an unconditional love, until I found out that I sometimes failed to love when certain conditions occurred. So I wasn't really being unconditional.
At the same time, this really wasn't unconditional love anyway, because it was applying mainly to only one person. Unconditional love does not just apply to one person. To be unconditional, it has to be impartial and it must apply the same to everyone, all the time.
In God, we are asked to unconditionally love everyone the SAME all of the time with no exceptions. That seems like a really tall order.
Can you unconditionally love, fully love, equally love, every single person including all the people that you had beliefs of blame or anger or annoyance or a grudge about? And not just the people in your close circles, but even complete strangers? That's what unconditional love means.
It takes a lot to admit that you are not unconditionally loving, and that you probably have practiced conditional love all your life. It takes some honesty to admit you do not love other people, maybe you don't love your neighbors or someone at work or certain groups in society. At least admitting that you don't can start to give way to you being open to learning why you don't, and correcting that.
Ultimately, YOU won't be fully and completely and unconditionally loved, or experience unconditional love, if you are not willing to both receive it AND give it.
When you love unconditionally, you represent God.
God DOES love you unconditionally, and that's pretty special ;-)