Life changes as you grow up, and nobody is there to tell you what's important and what isn't. You pick and choose as best you can, but sometimes you get to wondering if you picked up and put down the wrong things. You see other people who held onto things you let go, and they seem pretty happy. Cars, booze, music, painting, travel, fashion. You start to wonder if you made a mistake, and whether you can catch up again. But, for the most part, there was no mistake, just different choices.
It comes down to happiness, and some people can't be happy unless they have what everyone else has, or more. So if you gave up a social life to have a career, or gave up surfing to tow cars for a living, you might wonder if you'd be happier the other way around. For the most part, you wouldn't, because people tend to plateau at one level of happiness. It gets better, then you adjust and it feels about the same. It gets worse, and it sucks, but you get used to it. You throw away your whole career to go back to partying all the time, and it feels good for a while, but eventually it fades again.
So rest assured that the only wrong choice you really made was questioning your choices.
Mokalus of Borg
PS - Happiness is mostly a matter of being content with what you have now.
PPS - I mean, after a certain point. You have basic needs to meet, as a minimum.