[Question] What time in your life were you the most productive at learning and/​or thinking and why?

Example answers include “high school math camp, because we were forced to do X and because there was an atmosphere of amicable competition” or “that day when I locked myself in a room with a textbook” or “the day when I studied X, because I am really fascinated by X and ABC topics were boring to me when I tried to study them” or “the time I hired a tutor” etc

Asking because I’m considering building something that could amplify people’s learning/​thinking productivity.