There is, however, a simple formula for checking if what you’re doing is sustainable: how long does it take on a vacation or weekend until you stop feeling anxious, and how anxious do you start feeling when you think about returning to work on Monday?
What project would you be happy to devote 50 years of your life to, despite (or because of) it only being 10% done when you die?
Ht @hannu @gwern and Antoni Gaudi for inspiring the question