Lyrissa Lidsky blogs that:
I came to the study of law because it seemed like a good career for someone who loved reading, writing, and analyzing texts but was not creative enough to make it as a novelist nor independently wealthy enough to risk becoming a medievalist.
Goodness. If you tossed in sucked at math too much to be a theoretical scientist or economist and was too butter fingered to be an experimental scientist, you'd have an almost exact description of how I came to law.
It turned out okay, of course. Indeed, I suspect I make a good deal more money than 99.99% of the science fiction writers I wanted to emulate when I was a kid or the historian I briefly toyed with being. Plus, it's been fun.