That’s all there is to it. Tell us the single decision you would change if you could, and why.
I don’t have my answer yet, I just liked the question.
I got married before I went overseas, while we were both in the Army. If I had it to do over I’d wait until I returned and wasn’t quite so “head over heels in love”. The result would probably be that I wouldn’t have married the guy after all.
I wouldn’t start smoking. It’s messy, expensive and utterly unhealthy. And if you don’t start, you don’t have to quit.
I would not quit my job as an Art Director, to open a new company with my friend.
I started having some minor health issues five years ago and didn’t bother telling anybody or going to doctors till a full year later, thinking they were just temporary annoyances which would go away on their own. They didn’t, and only got worse and much more intractable. I wish I’d decided to seek treatment right when they started.
I would ask those Pitworthy folks at La Caixa for a fellowship (it’s one of the very few sources of money for a Spaniard looking for a master’s; master’s degrees are, with one exception, not even official degrees in Spain, so there’s no government funding), applied for another from Fulbright (whose attached strings are a lot lighter) and applied to MIT for that double program for which they sent me info (MS in Chem Eng, MBA) when I wrote Boston U asking for info about their doctorates. Those brochures had me drooling sooooooo badly…
I would have swam a little less quickly.
I’d have finished high school in San Francisco.
I would have called back the girl who worked at McDonald’s, who slipped me her phone number between two apple pies she gave me for free. She wasn’t the prettiest girl I had ever seen, and she seemed perhaps more than a tad eccentric, but given she’s the only female to seemingly have ever been attracted to me, I wonder how different my life might be now had I actually gone out with her and perhaps gained some actual experience with girls (I was 16 then, now 24).
sigh
I would have focused on dating after college rather than trying to go off and make a million dollars through hard work and stubbornness. It takes a lot of time and effort to make it big, and doing that for no one’s benefit/applaud but my own wasn’t enough after a few months of sleep deprivation.
I suspect this is largely a write-only thread, but I’m intrigued as to what this refers to.
I’ve had thoughts like that before (this was a friend of a friend, really cute, I was just horribly shy. She went after me and I was a dumbass and that was pretty much my shot at a relationship in high school), but things worked out for me in the end. I met my fiancee (I’m 22) through a friend of a friend the same night I decided I didn’t want/need a girlfriend and it’d be stupid for me to have one. I was just going to focus on school. And then she walked it.
So yeah, you never know.
To my past self:
TALK TO THAT GIRL YOU STUPID STUPID DOPE!!! SHE’S GIVING YOU EVERY POSITIVE SIGNAL!!!
I suspect this thread is going to have a lot of response like mine, Red, and Rand’s. 
I have precious few regrets in my life, but one that seems to consistently come up was to have gotten involved in a monogamous relationship as a freshman in high school which continued for the next 14 years. I really wish I would have dated like normal people.
I am guessing it is the speed at which he/she swam for the egg.
Oh. Dramatic, that.
I wouldn’t have let being hung up on one boy keep me from noticing other boys around me. I won’t say that messing with each other’s minds from the ages of 15 to 23 didn’t have its moments, but…
I would have followed my dream and taken a woodworking apprenticeship, instead of following my parents’ and going to college. College turned out fine, but now I am saddled with large amounts of student debt, a degree that I don’t really want, and am no closer to my dream.
Sweet Jesus.
I would have applied for the engineering job in New Jersey after graduate school.
I had the biggest crush ever on this girl I had known in my late teens. She was way out of my league, and I was awkward and shy at the time, but we had a ton of fun.
I found out way too late, she actually had a crush on me from a mutual friend. In hindsight, I probably passed up a thousand times to make a move. I’ve been internally kicking myself ever since…