Lots of good answers here already. In a lot of areas in life, the situation is like with man pages. The important thing to learn and remember is broadly what sh

Lots of good answers here already. In a lot of areas in life, the situation is like with man pages. The important thing to learn and remember is broadly what shell program/command you need to do the task at hand, what they can do. You can look up the exact option/format details in the man page as needed. There's not much point trying to memorize every last detail, most of which you will never use.