If i could go back in time and change something, i would just tell myself to work harder and take it more seriously. I would often shy away from things if i didn't see the benefit. I did enough in school just to get by. I was in advanced placement but i got bad grades in those classes. I simply didn't put in the effort. I missed the opportunity to learn a lot of cool shit. My dad would ask for help doing things but i was too busy doing other things.
Now I'm 30 and can barely turn a screwdriver. Had i been more curious and had some foresight, i would've been much better able to take care of myself and my belongings. My fiance and I recently bought a house and now i'm forced to learn everything for the first time -- instead of already being fully capable.
I can say the same for sports. I was naturally pretty good but i didn't do enough "when nobody was looking" to improve. I was good enough to be a starter in high school but i never earned a scholarship to play in college. I wish i would've tried harder. To have had the "front sight focus" needed to achieve my dreams. I always wanted to be a professional baseball player -- just not bad enough to actually have done anything about it. I felt like being one of the better players on my team was good enough. How naive of me.
Anyways, can't really complain about the past. Only try to learn from it and not continue to make the same mistakes...
