That I shouldn’t care as much about installed packages I no longer use. Sure, going through installed programs and cleaning up from time to time is ok, but no need to panic if something sticks around.
Especially when I installed something manually needing dependencies for programming, I tend to write down names of installed packages and then managing it manually, because I wasn’t yet aware what their names mean. Now using same OS for over a year, heavly testing stuff, having multiple desktop enviroments and not cleaning it up my system partition is taking less than 30GB, compared to 1TB disk it’s nothing.