Life is full of pithy but overly simplistic bits of advice like the above. How do you know what it is you love? What if you love too many things? I had more than a few crises as I neared the end of my first year of college (I can't believe I've finished a year of college), but I finally made up my mind to double major in French, which was basically a given (and on the practical end of liberal arts), and math, because I really think it's what I love. I realize many people find math unlovable. I loathed it through middle school, was skeptical through pre-calculus, and only really started to appreciate it when I got to calculus. They don't usually teach you the cool stuff, like linear algebra, in high school. Remember chemistry class when your teacher told you the only way to balance chemical reactions was an educated version of guess-and-check? Actually, there's a simple, foolproof method involving matrix reduction that will give you every possible way to balance an equation every time, including some solutions it would be basically impossible to arrive at by the eyeballing method. Nifty. Well, a lot of subjects have cool tricks up their sleeves. How do I know math is what I want to do for the next three years of my life? It was a small clue when my first meeting with my potential adviser turned into an hour-long lecture on the braid group and I didn't get bored. That evolved into my going to office hours on the (legitimate) pretense of getting homework help, but really just so I could sit and listen to the math professors talk. I heard rants ranging from how the sciences are corrupting pure math, to how math in movies is invariably wrong (and how the professors here invariably know the people hired to be math consultants in said movies), interspersed with mini-lectures about arcane principles of mathematics. As terrifically nerdy as it sounds, those were some of the best conversations I had all semester, and those are the people I want to spend the next three years learning from. I will leave you with a joke that, even if you never find mathematics lovable, you have to admit is pretty hilarious:
Q: What do you get if you cross a mosquito with an elephant?
Q: What do you get if you cross a mosquito with a mountain climber?
A: Trick question. You can't cross a vector with a scaler.