The last time I stayed up past midnight to work on something was probably close to a year ago. I stopped when I made what I thought was a simple change and ended up completely fubaring the font end of the site.

I went to bed and first thing the next morning fixed what was an insurmountable obstacle just a few hours before. Maybe it's because I wasn't on a deadline, maybe it's because I could sleep as long as I wanted because it was a weekend, but since then I haven't had any reason or desire to work past the point where my body wants to go to sleep.