On my office wall hangs my degree -- first class honours from a good university. I still half expect that one day they will ask for it back, that they were just being nice because they like me.
My Dad has it bad -- very bad. He has > 50 years experience in his field. He knows more about electricity than most electrical engineers. I tried to convince him to join the IEEE; with his experience and knowledge they'd probably bump him up to Senior Member grade quick smart.
Nope. Not good enough.
This can actually be quite crippling -- he used to give away his services rather than charging for them. "Too simple a job, I couldn't possibly charge for it". He was not a successful small businessman, thinking like that.
It takes most of my willpower to ask people for money. Because surely, I'm not that good. Surely.