I ran Gentoo for a long time in the early 2000's. I learned nearly everything I know about Linux machines in general from that experience! What was interesting

I ran Gentoo for a long time in the early 2000's. I learned nearly everything I know about Linux machines in general from that experience! What was interesting about the USE flags was learning that a given package even HAD a particular integration with some other library / package. Realizing that the SQLite3 binary doesn't work the same when you don't have readline support linked to it lead me to understand what readline was as a whole. That happened over and over again for a lot of the "invisible" libraries that are always included on every other Linux system. Absolutely invaluable learning tool at the right time in my life for sure.