Why and how are spreadsheets useful for a programmer, and should I learn to use Excel?

[zaerth]

I've never had a programming job as I'm still pretty noob and still learning, but it looks like, from what I've read online, a lot of programmers use spreadsheets everyday while working. Why? How do they use them? Should I learn how to use Excel? I only tried them a couple of times for some stupid and trivial things, like creating some tables and stuff like that.



My guess is that they are used to store some data or keep track of various progress and achievements in a project, but I really have no clue. Sorry if it's a stupid question but I can't understand why are spreadsheets so popular in programming jobs.