I agree, except for learning = pain.
I find that, like most things, it’s all to do with context.
If I’m “forced” to learn something (e.g. exam, deadlines,etc) I find it painful.
If I’m doing it on my own, with no pressure, I find it enjoyable.
And I think it’s independent of subject (having started some subjects as a requirement but then moving on to learn them as a hobby).