The Next Big Thing

I've been thinking I should pick something new to become an expert in. In the past, I've kind of fallen into things (like, most recently, learning about taxes), but now (or soon) I should be able to make my own choice.

Is there anything so fun that I would like to do it many hours a day? That I would like it to mold my perception of other things (like how quilters see everything as possible quilt designs and rock climbers see hand-holds in everything)? That I would like to hang out in discussion boards about? That I would like to go to conferences on?

I've made no serious decisions yet, but ( here are some possibilities I've thought of, in alphabetical order )

So, next steps currently (though perhaps not until after I quit worrying about making more money) is to volunteer at a school tutoring math and see where that leads, try writing some nonfiction books and some songs, and learn some Spanish and then maybe some ASL.