Never admit that you're an expert at anything. Tell everyone you're an amateur. That way when you fail nobody is disappointed and when you succeed everyone is impressed. amirite?

Yeah this works great on job interviews.

"So, we're looking for a person with expert skills."

"Well, I'm an amateur."

"Perfect. You're hired."

Great way to be unemployed as a contractor

I think the more nuanced way to phrase this is to not oversell your skills.

I never tell anyone about how good I am at wacking off. And I get the exact opposite result.

A way to say you are good at something without sounding like you are trying to brag or show off.

I am at least competent at what I do.

Not sure people want to hear that from their doctor

My exact logic at work!