spin is something that behaves like spin. the right answer is shut up and calculate

It's mind blowing to me that particles with no inherent physical shape or dimension can be considered "spinning" not because we observe them spinning but because they have literally all the characteristics of a spinning particle other than actual rotation around an axis

Spin is easy, it just only shows in our current formulation of quantum mechanics, has no classical counterpart, is sort of a type of angular momentum, but isn't, whatever shut up.

Seems simple enough to me.

Is that why spin doctors get paid so well?

Meat has been shown to have spin also. They made a website about this