In your teens and early 20's you're partying hard with friends, getting laid, and making lots of good memories.
Whoah, we must be living on different planets. In my teens I had zits, I couldn't talk to a girl to save my life, parents and teachers kept telling me I sucked, I had no money, no transportation and I could never do anything I would have wanted to (too dangerous, too expensive, too far, etc). Maybe it's the reason why I still seek new bands in my 40s... (scandinavian metal rules!)
I overheard a conversation recently. There were a girl upset that a guys at a party totally missed the fact that she wanted to be asked out. She flirted shamelessly, but the guy ignored her and instead asked out her friend - who promptly turned him down. They then both called the guy "an idiot".
Reminds me of something that happened when I was a kid (of 16). While on a trip I asked a girl out. She said no. Fine. Then at the end of the trip she asked me why I didn't ask a second time... Turns out she wanted another guy, but when that one went out with another girl she would have settled for me fine.
Relationship are complicated. Events like this make you grow up. After something like that you may be bitter for a while but then you start to understand people better... and economics too !!! If you spend your time doing video games, you won't grow up.