I used to feel the same way. I still feel that there's no off switch, but one can still count hours. With students, peers, and superiors these days, I actively

I used to feel the same way. I still feel that there's no off switch, but one can still count hours. With students, peers, and superiors these days, I actively encourage everyone to go home. Our research group, by default, easily encourages everyone to work 50+ hour weeks. I think it's less productive than 40 rested and focused hours. You can think and dream at home, or lie awake in bed, but it's important to carve out time for everything else in life, too.