The Wealthy Plumber 富裕的水喉匠
A plumber attended to a leaky faucet at the neurosurgeon's house. After a two-minute job, he demanded $150.
The neurosurgeon exclaimed, "I don't even charge that amount and I am a brain surgeon."
The plumber replied, "I agree, you're right! I didn't either when I was a surgeon. That's why I switched to plumbing."