Dude, what you've let yourself in for will become apparent as time goes by. But by then it will be too late.
Seriously, it's all about fun and learning (and if those two are the same for you, so much the better!). Some take the "detective" angle, some the "impressions of the music" angle, but whatever tact anybody takes in these things, they take because it's fun for them to do it that way. But geez, I've learned a TON with every one of them that I've participated in. And on #24, I expect to learn several tons, because I don't have a clue what most of the stuff is! So, fun and learning, that's the object of the game.
That, and free tunes. Can't go wrong with free tunes.