Oh, I wasn't forced to work 16 hours. It wasn't crunch-time, or anything. The company and the team was reasonably supportive about work-life balance.

But the project I was working on was very interesting, my tasks were also pretty interesting, the team was mostly assembled of competent people, and I enjoyed every second I spent on the project - I actually tried to spend as much time on it as I could. Was almost like an addiction... I just kind of neglected many other things.