List of Math Things I Have Yet to Use

I thought the "use of math" thread below was interesting, I decided to make a list of math things I have yet to use. Up to high school I had more or less a typical American high school education (Geometry/Algebra/Trig/Calc) and in university I studied law (so pretty much no math).

Yes, we all know we need to calculate our retirement plans, the dimensions of prospective furniture, ppm in the weather... but when should I have to dig out my old math textbooks (I still have them, just in case) to use these?

1. Vectors. They made us learn them, know only vaguely they're used in engineering and calculating some kind of dynamics... how can I use them "in real life"?

2. Anything trig. For me, trigonometry was harder than anything else I had to learn in math, of course I didn't have a good teacher that year. But I did learn it, so when can I use it? When someone says radian these days, I assume it's a French person saying I look shiny.

3. Calculus. I do invest my money but I never get to the point of having to calculate the slope of something or integrate something. We once had an assignment in high school where we had to calculate the different amount of water running over an underwater propeller - that was really neat - it got me a taste of how useful calculus was. But I've never used it since.

(edit) 4. Limits.

I think learning something for its own sake is a good thing, and I'm glad I got to learn as much math as I did... I can agree that it made me a more rational and smarter person, and that in itself is meaningful enough for me, especially speaking from this side of my exams :) But can these skills be used in "real life" as they are?