Many people save their history. The command shell I use, 4NT, also has logging options. However, if I saved everything, what I'm interested in might get lost in the forest of meaningless day-to-day commands.
in reply to The problem with one-liners...
So, I think I'll turn logging on when I'm developing a "one liner" to have the work automatically saved, then turn it off again. If I need to do something again, I can find the last line of the bunch of similar lines and copy that out, and save it to a one-liner file.