I too "wasted" most of my teens writing "pointless" programs - games in Basic that I never finished, assembly language programs optimized for old computers 20 years obsolete, and C++ programs with extensible architectures that no one else will ever extend.
My father always warned me that one day I would wake up and realize I'd wasted my life sitting in front of a computer screen. Bullshit.
When I was in college I ran into people I'd known in high school who told me some stories about what was really going on in the social circles I'd missed while I spent my days with a computer, and I was shocked. Most of my "normal" peers who had social lives drank heavily and got into drugs - some died or nearly died. Many of them became teen parents. I never even knew! My obsession with computers had kept me insulated from all of that.
Now that I'm a working adult and married, I look back with wonder at the thought of having long summer vacations where I had no responsibilities preventing me from hacking for days on end. Though I didn't appreciate the time I had then as much as I would appreciate it now, I would not change a single minute of how I spent it. There is a depth of understanding I built up during those years doing "pointless" hacking that I simply could not have picked up in the piecemeal way my time is split up today. Every year that I spent working 12 hours a day on interesting problems while I was in high school put me ahead 6 years on what I could accomplish today, when I'm lucky to get 1-2 hours free a day. Whenever I run across a problem today that I can solve in a snap because it mirrors a problem I already solved at my leisure during those early year, I think, "Damn it's good to be a geek."
When I was 13 I had a crappy old PC that I used to take apart and fiddle with. When it bust altogether, I pretty much forgot about computers.
I reached 14, I lost my brother, and as I watched my family crumble I turned to drinking and smoking weed. Yes, at 14. I hung out with the wrong crowd, I did things I shouldn't have and I spent my school time living up what was deemed the "ideal" social life by my peers.
A year or so later I got really in to computers again. I started making web pages; I got a new (old) desktop which I tweaked up and geeked out on. I progressed from HTML and CSS to PHP (and yeah, I know that PHP has a bad rap amongst most hackers here, but I like it), spent all my time in IT at school etc. I gently progressed in to a real computer nerd.
Looking back now, I can honestly say that the time I "wasted" messing about with computers, teaching myself how to code, etc.. they were the best of my teenage years, and I have no regrets on how I spent my time. It is who I am, I enjoy doing what I do. I wouldn't change for anyone.