nowadays instead of getting that work done in an 8-hour shift I take about 10–12 hours to do it.

"For disappearing acts, it's hard to beat what happens to the 8 hours supposedly left after 8 hour of work and 8 hours of sleep" -- Doug Larson.

An 8-hour shift quickly turns into 10-12 clock-hours when you factor in all the extraneous crap that goes along with it. I mean, just lunch and a commute easily adds 60-90 unpaid minutes per day. Add the time spent getting ready for work and settling down after work, and you're easily up to 10 hours a day.