I saw this asked on another instance, thought I’d ask it here and I’ll post my response from there in the comments as I think it felt cathartic.
Doesn't need to be a life or death situation, just any moment in your life where you found yourself saying "Holy shit, I can't believe this is happening!"
Probably climbing up the West Ridge of Quandary Peak in CO. I was with 3 college friends. I didn't expect the altitude to affect me as much as it did, but I got pretty winded. It was a little snowy and wet, so our holds were sketchy at times. Along the ridge it's class 3 climbing, and the crux is a crack in a steep rock with a dangerous fall behind you. That was probably the biggest adrenaline rush I've ever had.
Thankfully we were greeted by some friendly mountain goats on our descent.
Here's a good video of the climb. The harder stuff starts about 9 minutes in.