I agree. I find that I have a fairly fixed amount of energy. There are various lifestyle changes that affect this energy, but at the beginning of a day I'm pretty much set in how much work I'll get done that day, whatever it's on.

The biggest efficiency gain for me is eliminating things that have a large cognitive drain but little efficiency, such as face-to-face meetings, phone calls, and generally things that can be automated.

Having the printer closer won't help much.