As someone with a private teaching background (>100 pupils, mostly 1to1) I have always wondered about that. There are huge individual differences. It never ceas

As someone with a private teaching background (>100 pupils, mostly 1to1) I have always wondered about that. There are huge individual differences. It never ceases to amaze me. My pragmatic advice (without going into my theories): just observe yourself throughout your activities, take daily notes. If you don't like to write essay-like diary entries just reduce it to an organized excel spreadsheet e.g. specific activity, time spent, rating system (long-term/short-term satisfaction, hard/easy ...), misc: (interesting) things you observed about yourself; you get the idea. In most cases it really helps to clear up some confusion and misconceptions you have about yourself. "Fun", "Happiness", "Flow" etc. is a spontaneous state dependent on a plethora of things working in sync nobody can teach you directly because in the end you are the driver balancing all those things. Once you get a better sense what versions of "fun" you enjoy, observe and ask others: How do they go about this? What is fun for them? Maybe you find some interesting strategy you can apply or get an appreciation on how individuals can vastly differ from you.