Those are both the same reason; if you don't do some shit before dying, you won't have another chance.
Even more: the saying should be YOLNO (You Only Live Now Once). Miss your opportunity window of doing something, and it's gone, whether you keep living or not.
“I’m gonna regret this in the morning/immediately”
“Hey babe wanna see me do something stupid”
“I’m an engineer I know what I’m doing”
“It’ll be cheaper if I do it myself”
“How hard could it be”
“One more won’t hurt”
“Worst case scenario I die”
I use "not here for a long time or a good time but I gotta do this because of reasons."
Gotta risk it for the biscuit
No idea why or when I heard it but I like the risk/reward nature of it
What's the worst that could happen?
completely rhetorical, doesn't actually consider what could go wrong