Nobody can be an expert in every single tool they use, furthermore it's a waste of time if you have the option of learning things when the need arises. Not only

Nobody can be an expert in every single tool they use, furthermore it's a waste of time if you have the option of learning things when the need arises. Not only would you have forgotten most of the text of man pages after reading it, you're also unlikely to ever use most of the options you found in them. The important first step in learning how to use a command line tool is to have a first working example, i.e. you've made the tool do something you wanted. From there, all you need to know is how to find out more about what it can do. Skim read through some examples, anything else you think could be useful? Try it out. The rest can be forgotten. There's no harm in keeping knowledge outside our memory if we know how to research it if needed.