I think it comes down to rationalizations: I know that I can rationalize doing something new and different. I can convince myself that a failed venture taught

I think it comes down to rationalizations: I know that I can rationalize doing something new and different. I can convince myself that a failed venture taught me something, whereas I have no way of telling myself that I shouldn't regret a missed opportunity. It's much more common to be stuck wondering "what if" as opposed to "what if I hadn't".