So far the most confusing portion of git is rebasing onto another branch. Specifically, it's the command line arguments that are confusing.

Each time I want to rebase a small piece of one branch onto the tip of another, I have to review the git rebase documentation and it takes me about 5-10 minutes to understand what each of the 3 main arguments should be.

git rebase <upstream> <branch> --onto <newbase>

What is a good rule of thumb to help me memorize what each of these 3 parameters should be set to, given any kind of rebase onto another branch?

Bear in mind I have gone over the git-rebase documentation again, and again, and again, and again (and again), but it's always difficult to understand (like a boring scientific white-paper or something). So at this point I feel I need to involve other people to help me grasp it.

My goal is that I should never have to review the documentation for these basic parameters. I haven't been able to memorize them so far, and I've done a ton of rebases already. So it's a bit unusual that I've been able to memorize every other command and its parameters so far, but not rebase with --onto.