Min-maxing is a reliable way to suck the fun out of most things for me, too. Way back in High School my friends and I would get together and play bridge. We were certainly competitive, and became decent players, but it was as much about the trash-talking and socializing as about who won or lost.

Later I took a course with an ACBL life master, and learned the complex and completely artificial bidding systems and other ways to communicate every possible bit of information through quirky and limited channels. I guess some people find that fun, but to me it was mechanical and WORK. The game was less of a game.