I prefer to think of rebase as accomplishing one simply-described task:

Taking a series of commits from anywhere in the repo and replaying it starting from any point in the repo, possibly with modifications.

All the use cases described in the article and crazy CLI options fall out of this simple description. I realize there's quite a bit you need to grok before this becomes obvious, but nevertheless I think it's a good mantra to have as you are learning git and run into problems.

Eventually your mental model shifts from "what does this command option do?" to "what final state of the repository do I want?", and from there it's just a matter of practice.