I comment my shell commands, thus:

    $ ,:(){ :|:& };: #forkbomb

This way, when I want to find it again, I CTRL-R and type ‘forkbomb’ .. voila, instant recall!

All I have to remember is the small ontology I keep in my head for the most important commands I use .. pretty easy if I also construct a narrative for those commands, contextually. “#downup #clearlog #checkconn #amialone #forkbomb”, etc.