I could pull that off in my early twenties while studying and working full time and still have energy for other activities.
Now at 30, if I get less than 8 hours of uninterrupted sleep a few days in a row, I'm a zombie and I feel the negative effect in all my activities: brain fog at work, depressed, no lust for social gatherings, sports or sex.
- Adding value for others is the best way I've found to achieve greater success
- (and this is very recent) consider price as a measure of value, like a liter is a measure of volume