I actually have a friend who works as a financial auditor. I asked him one day, "Why become an auditor?" and I was pretty surprised by his answer! He really enjoys finance and keeping everything in order. He enjoys finding those little discrepancies in financial records.
He feels like it's almost financial detective work. Sometimes you just find careless errors, but every now and then you uncover a case of fraud!
It doesn't sound terribly exciting to me either, but my friend seems to enjoy his job.