How might you know if you have asperger's syndrome?

DSM4: Dsm 4 criteria for the disorder is available online, ("google"it), if still in doubt, you should visit a psychiatrist and get a formal evaluation. You may also find that you have other things to work on instead, or can use some help without having aspergers; who knows?

It's moot: There's no pill or magic cure. The real question is perhaps, "What do I do if I'm socially awkward, physically clumsy, and really good at focusing on narrow topics?" Social skills training's widely available. Choose a strength / endurance sport rather than a team / coordination sport. Focus on science / tech rather than superstition, comics, or train schedules, and you'll do great.