nostr:npub1upkp7fd7rc3lrjg23r8gy0wc723vze7mxlx5984ut6zurjzpf5xss4tcwy I found the interactive cheat approach interesting. For example :
https://github.com/cheat/cheat
Because it became trivial to make your own with the command you need. And then it helps remember it.
But for the pipe mechanism or AWK, books is what helped me most. For example from A. Robbins, O'Reilly.