Great question, eh? Well, it is if you are thinking about becoming a mathematician. I am not. My job is publishing books about math, although I do get asked to divide the check at restaurants.
But I asked this question of my local mathematician, George. He gave me two reasons why he took this career path.
1. George thought that mathematics would be definitive, precise, and free of ambiguity. Sadly, he was wrong. "The deeper you get into a subject, the more vague it becomes," he sighed.
2. Math looked like it would be fun. Not so much the calculations, which can be tedious, but the people.
"Some REALLY STRANGE people do mathematics!" George enthused (not meaning himself, of course). He went on to list a few ...
George's Bio: I obtained a PhD in mathematics from Carnegie-Mellon University with an emphasis in Continuum Mechanics. I worked at the Space and Naval Warfare center for 44 years. My principal job was mathematical modeling of Sonar transducers and arrays. This involved elasticity theory, electrodynamics, acoustics, and numerical analysis. I was a co-developer of a program (CHIEF) that numerically solves the Helmholtz integral equation to predict acoustic radiation or scattering from arbitrary-shaped bodies.
No, I am not making this up. I don't understand it either.
Mathematicians are not on every corner. Ask around. See if you can find a mathematician. Odds are, you can't.
About 45,000 research-oriented PhD degrees are conferred each year in the United States. Under 1000 are in mathematics. That's ok because there are only about 3000 jobs available if you want to do heavy-duty math research. Most of them are with the Department of Defense or NASA. If you can get one of those jobs you can expect to earn about $100,000.
See, math can be fun. And lucrative.