Great read (: This is precisely how I learn, even though these days it all feels a little futile.

The other part for me is working within tight constraints. A couple of years back I made an Operating System that fits a bootloader (I was low-key hoping to find in the list :P) Not really golfing but surely a good exercise in playing within constraints.

If anybody wants to take a look https://github.com/shikaan/osle