This is a fantastic, amazing, wonderful, and never mentioned point. I am beat after 8 hours of mental output. I mean, I sit in a chair (or stand) at my desk mos

This is a fantastic, amazing, wonderful, and never mentioned point. I am beat after 8 hours of mental output. I mean, I sit in a chair (or stand) at my desk most of the day, and take frequent breaks, and I'm still tired. Why would I expect more of a child?