Mmm...
Well, I think about this a lot when considering CTB, tbh. I'm not religious of any sort; I know its just black, like a dreamless sleep.
But I often find myself wishing :
1) Take what I know about how my future turns out and go back to just after my tonsils were removed.
2) Somehow transport the feelings/memories/knowledge of this me to an alternate dimension me sometime during high school so she can seek the help she needs before it festers further and hopefully live a better life through different, more responsible choices.
3) If time is cyclical, that when I'm reborn, I retain something, anything, from this life, through dreams or deja vu, that will will make me feel just 'off' enough to get me out of certain situations and lower at least some of the trauma I'm destined to face or make me stronger. Just a slightly better hand that I get dealt so I can play the game a little longer or a little more confidently.
I'm sure those are silly wishes. I could wish for like, a billion dollars to get things that might make me happier, or a friend who understands, or to just magically heal my brain/erase my memories and trauma. But I think your body kind of... remembers, even if you don't. I think the sadness and the loneliness would still be there, I just wouldn't know why. That's kind of frightening in its own way. I'd rather have the chance to get strong enough to combat it, instead of like it is now.