I want to learn how to play the banjo, and become adept at it. I have always considered myself to be inept when it comes to musical ability, but in retrospect I think I have limited myself in several ways with that mentality. I want to broaden my horizons.
Only one? Well...
Rebuild a transmission. Not that I need to do that specifically, but if you can do that, you are one hell of a mechanic.
That one is obvious. I would choose to be master of learning skills. The most efficient and effective way to learn is a skill in itself and I think very few people truly have a high level at this.
How to talk to women,I'd be rich.