I tried to be a tailor...
I tried to be a tailor, but I just wasn't suited for it. Mainly because it was a so-so job.

A doctor is complaining to a mechanic
A doctor is talking to a car mechanic, "Your fee is several times more per hour then we get paid for medical care."

"Yeah, but you see, doc, you have always the same model, it hasn't changed since Adam; but we have to keep up to date with new models coming every month."