Compliments

The only true compliments are the ones said behind your back.

If someone compliments you to your face, it could be so many insincere things. It could be flattery for an eventual favor they plan to ask of you. Social positioning, ingratiation. performative humility. The list goes on.

If, however, while you were not present, someone were to speak highly of you to another person, then you can be fairly certain that the kind words are genuine.