It's likely bravado from college days. I remember overhearing many conversations at school where students would brag about pulling their second all-nighter in a particular week. I could only think that they were doing something wrong. If your work load is requiring you to stay up for more than 16-18 hours a day, then you're either doing too much or you're really inefficient.

A metric of success, to me, is being able to make money while you're asleep. You'll never escape the chains of the cubicle if you don't work smart.