Back when I was still playing MtG, I developed a reputation for playing games a certain way.
I played three or more games a day, every day, for three months or so. I lost every game. Every. Single. Game. And then I read absolutely all of the rules, went back and lost every game I played for another month, and then took apart all of my decks, and reassembled the cards into decks which used all of the strategies and tactics of the decks that frustrated me when they beat me. I learned every card I could, until I developed an encyclopaedic knowledge of every set in type 2, and the four sets that came before it.
From then on, 17 out of 20 games were an easy, calculated win. Another 2 were calculated, but not easy. I lost only when I drew no usable cards for at least four turns.
When my friends were making decks that abused certain combinations, I was making similar decks that did the same thing, but faster. Eventually, I started piecing together a decent all-around useful strategy: punish my opponent(s) for owning a library and using it. (It's UBR.)
People could immediately identify when I had helped someone else build a deck. There was just something about the "feel" of decks that I had helped put together.
When I picked up D&D, the same sort of progression happened. I'm still trying to learn all of the rules and materials, but my friends can still tell when I've helped someone build a character. But the best part about this game, to me, is that most of you are still better at it than I am.
So, whereas I'm sure that I have a character somewhere that I haven't min-maxed, the act of building one would probably be hard for me, now. That doesn't mean I'm an always-optimal kind of guy. I put together lots of sub-optimal builds. I prefer them, in fact. I know how far from that top they are, but most other gamers I've talked to still look at me like a crazy power gamer, should I ever describe one of them.
Case in point, I'm going to be starting a gestalt game at ECL 11 soon. The DM is the younger brother of the guy I usually play under, but his table will be new to me. I don't know how much he and his brother talk, but the guy who set up this game told the DM to make the campaign as difficult as he pleases. When I started helping another player build their character, I asked him what he wanted to play.
He said, "I've always liked the idea of playing a sorcerer or a wizard, but I'll probably end up being a rogue/fighter." I asked him why that was, and he told me, "Well, wizards are an okay concept, but this is going to be a tough campaign, and compared to fighters, wizards just suck in combat. A fighter can attack three or four times in a round, but a wizard can only cast one spell."
I just about had an apoplexy. This is definitely why I like to play sub-optimal characters.