"based on prior knowledge on a subject" seems to causing the issues here. I'd expect people with 10 years of programming experience to pick up a new programmin

"based on prior knowledge on a subject" seems to causing the issues here. I'd expect people with 10 years of programming experience to pick up a new programming language much faster (overall) than someone with only 1 year. I wouldn't expect them to be necessarily faster at picking up a topic that has nothing to do with programming. So there's a big difference between "People who already have a bunch of experience on a topic learn something on the same topic faster" and "Some people just plain learn things faster than others". So they're controlling for "amount of experience", and saying that as long as you have a similar amount of experience on a topic as someone else you'll probably learn about the same speed as them. And you're saying "But the amount of experience you have makes you learn faster!" - and these two things don't seem to be in opposition, to me.