Piano, saxophone, geology, astronomy, japanese, game development on old consoles, hiking, weight training, personal site redesign, writing novels, writing stories, designing board and card games, mobile app development, virtual reality development, drawing, composing music, game production and publishing, cooking, etc.
It should be noted that for all of these things listed there was at least a small period of my life where I spent a good chunk of time doing them.
Instead right now I seem to only have the time, energy, and motivation for board game design (and recording it in a diary), keeping my puppy active and happy (walks, fetch), playing some games, fixing a bug or adding a small feature or two in a mobile app once a week, and writing one short story for an anthology once a year.
And I only work 40 hours a week. When I worked 60+ I didn't have energy to do anything but eat dinner and sleep.
Coming home after 8 hours of work to 1-2 hours of chores isn't fun.
Even with a couple extra hours at home a week it's hard to find exactly what I should be doing. I tried to put together a schedule of taking some online classes I've watched to for a while, writing, spending 30-1 hour playing games I've been meaning to play, and generally calling / talking to friends and family more. However I still find myself in a loop of checking reddit, youtube, facebook, and hackernews over and over around 7PM.
I understand its a problem born from extreme privilege but if the future is filled with more free time it's a problem that many will run into.