Exactly this. Any self-taught intermediate person will have learned some things, missed others, and the pattern of what is missed varies widely by person. Therefore it isn't, "Oh, you're intermediate, this is what you need." Instead it is, "Here are the basic things that you happened to miss."

So it may be valid to swallow your pride and do the basic course, most of which you know, to find what you don't.

Or to trust that you can fill in holes yourself on demand. (People's belief about how well they can do this tends to exceed their actual ability...)

Or to have someone evaluate you to find those blind spots.