We had a conversation at a Danis Bois Method / Perceptive Pedagogy class to that effect and it was true for the teacher and the other person in the room with a decade exposure.

Both of those people earn their living with working with clients, so counting money and time isn't trival. The teacher has I think twelve years in the method and was previously teacher yoga and before that a dancer. Yoga didn't do the same thing for her that she's now getting.

I unfortunately don't have data about people who do it for a decade at that age who aren't working professionally with it.