It's one of those things that has just...never really come up. I keep meaning to, and once I had another friend whose car is stick try to teach me, but I never really got there. And I do (and want to continue to do) a lot of traveling, and, outside the US, cars with standard transmissions are like, half as expensive to rent. Heck, a standard car costs less to buy new, even in the US!
I'm not exactly sure what my plan is for this one - nobody I know who's local drives a standard (Even my stepdad's porsche is, weirdly, an automatic.), so I have no idea where I think I'm going to find one to practice on. But, again, it's one of those things like riding a bike where, in an emergency, I do not want to be incapable. (I am not sure what kind of bike emergency I think I'm going to encounter, but you never know.)