teacher

Prov. You will learn more from things that happen to you in real life than you will from hearing about or studying things that happen to other people. I don't care how many books you read about how to run a business; experience is the best teacher. The nurse believed that experience was the best teacher when it came to developing a bedside manner, so she made sure that all her students spent a lot of time with patients.

Prov. Only fools do not learn after seeing other people's mistakes and insist on repeating them. Father: You should spend more time studying and less time having fun with your friends. If I had been a better student when I was your age, I'd have a better job now. Son: Oh, come on, Dad. School's worthless. Father: Don't make the same mistake I did! Experience is the teacher of fools.

the teacher's favorite student. (*Typically: be ~; become ~.) Sally is the teacher's pet. She always gets special treatment. The other students don't like the teacher's pet.

to be acting as you do when you are working as a teacher, lawyer etc., which may be different from the way you act in other situations I was wearing my teacher's hat at the meeting.

A person who has gained favor with authority, as in Al has managed to be teacher's pet in any job he has held. This expression transfers the original sense of a teacher's favorite pupil to broader use. [1920s]

Someone who seeks preferential treatment. A derisive epithet hurled at a student who tries to curry a teacher's favor in hopes of a better grade. Such a charge, valid or not, often led to cloakroom or schoolyard challenges and bloody noses. Outside of school, it was applied to people who insinuated themselves to authority in the hope of special treatment. The French equivalent is “teacher's little cabbage.”