There are two kinds of teachers. Those that are genuinely interested in teaching and have a passion for it, and those that have failed in their chosen career and who instead now teach it eg: a failed accountant teaching accounting. Unfortunately there seem to be more of the latter. Amirite?

"Those who can't do, teach. Those who can't teach, teach gym."

"Those who can't teach, teach high school."

My biology teacher was actually a scientist.
But she sucked at being a biology teacher. She is why I don't want to take AP Bio.

You don't have to have passion to want to teach something.

Isn't there a saying like that?
Those who can't; teach. ...or something alone those lines.