I have found this to be true of nearly all “smart” career people. Engineers, Academics, Doctors, basically anything that requires intensive post-graduate study. (The only exception is lawyers, most lawyers I know actively discourage people from pursuing law, "OMG no, don’t, its terrible!)
I have had many go-rounds with PhD holding academics about my lack of credentials. “Where did you do your undergrad” “I didn’t.” “…oh, but you’re so smart.” “I know, thanks.” “I was going to recommend the PhD/MBA/Masters program…” “Thanks, I’m good.” - its hilarious to watch people short circuit.
