You wouldn't drink and drive. Would you drive at 3 AM having had no sleep? Of course you would. And if you stayed up all night, working or playing, and managed to make it to the office the next day, would you drive yourself home at the end of the day?

Sure you would. I do it all the time, and I'm just like you. ;) :D

Seriously, though, I've done that a few times on crunch work weeks, and I recently made the mistake of engaging in this practice while maneuvering a job hunt. That's right, I showed up for a job interview last week--among people who know my name from .NET user groups and from former employees of my last job's workplace--after spending most of the night trying to cram code in Visual Studio so that my last week on the job (which I resigned from voluntarily, mind you) would be left in a professional, job-complete manner. Only I compromised the potential next job. Not smart.

I showed up and complained about the previous job. They didn't even ask for it. I was just trying to keep my eyes open while whining about how sad I feel that it came to this (my resignation). I'm lucky I didn't reach over and try to get a hug from the interviewing manager. The guy was like, "I've had enough, I'm done, any questions?" I tortured them after that with stupid accusations of having rumored reputations of boxing senior programmers into trivial, mundane tasks and not exposing them to the bigger picture, among other things.

So here's my advice to myself: You're an idiot. Seriously, dude, stay balanced, and don't drink and drive.