Lesson n. eight from my Masters degree
Ferociously guard your personal life. If at all possible, carve an hour per day, two on weekends, for yourself and fight for this time as hard as you can. And if you lose that fight - remember it and reclaim the time as quickly as possible.
The longer you live without those times where you just exist as yourself, doing the things you love, the less personality you will have left. In the end, the very people you sacrificed yourself for will turn their back on you. “You are not the same person anymore”, they will say. And they will be right.
It is not their job to guard your personality, it is yours.