"My most personally productive run was on a job that I had 4 hours in the morning to program and was doing something completely different in the afternoon." I

"My most personally productive run was on a job that I had 4 hours in the morning to program and was doing something completely different in the afternoon." I totally agree with you. If you super concentrated on solving one hard problem within 4 hours in the morning, it's hard to have the same amount of energy to do another on in the rest of the day. So we need to manage our productivity in a better way to balance the work load and intensity. We need to have time to get recharged.