Second, how many times did you pull a few all-nighters in a row during college? I can't even count. I certainly didn't die.
Every single time I have done that, in college or grad school, it has fucked me over far worse than if I had just planned ahead, scheduled my work well, and gotten plenty of sleep like a sensible person.
That's true but also besides the point. As a banker, you can't schedule your work like a sensible person. The client asks a question one afternoon and you work late into the night so you can get him an answer by the morning. It's all about latency, not throughput. The question isn't: is this efficient? It's: will it kill you? And the answer is: almost certainly not.
Every single time I have done that, in college or grad school, it has fucked me over far worse than if I had just planned ahead, scheduled my work well, and gotten plenty of sleep like a sensible person.