Ask HN: How do you decide whether or not to try a startup?

I've been agonizing over the past few weeks & months whether or not to "try a startup" -- and by that I mean executing on an idea, beginning to write the code, actually trying to solidify these ideas and traversing whatever the next steps I have to figure out are.

I'm 26, have a good job as a SWE, relatively stable life all things considered.. and yet I feel like over the past year I've been going through a sort of "quaterlife crisis" where I feel like I could be doing more with my life, and challenging myself in different ways.

It's probably due to the fact that I've been browsing HN and learning about startups very heavily since coming across this forum but I feel like that "challenge" is executing on this idea and founding a startup -- it's constantly on my mind but I've been hesitating to throw myself all in for reasons which I haven't really come to terms with.

It genuinely feels like there is this itch that I just need to scratch. I understand that starting a company is hard, I've read many times that a start up is the hardest thing the founder(s) have ever had to do, for some reason that is even more appealing to me because as mentioned at this age I'm left wondering what else is there in life and feel myself looking for a great challenge.

TL;DR: To founders and co-founders, what factors led to you ultimately starting a start up, how did you asses your feelings and come to the decision to just "do it"?