The unix tool history outputs a list of commands executed on the system. Originally I thought of this as unneccesary. Simply pressing <UP> to cycle through previous commands was what I did. I was used to this from the python interpreter and it seemed more convenient than writing a command.

History shows the context.

Seeing a single command is nice if you're only interested in that single command. Say you cannot remember what a program was called, but know you just called it. However often we are asking instead "what" we were doing instead of what command we were executed. Looking at the output of history you can easily see the commands executed before or after, giving you context. Which is especially brilliant if we are actually looking for a specific command, we know roughly what it does. But it happened some time ago. Maybe it wasn't even somebody else using the command. In that case cycling with <UP> is pretty much useless.