Being polite to someone you can’t stand is a skill, not hypocrisy.

Courtesy is not a claim about your feelings; it is a way of keeping a shared space usable. You can dislike somebody thoroughly and still say good morning, because the alternative costs everyone in the room something and costs you your own composure. Honesty does not require broadcasting every private verdict.

Practise it where you have to see the person anyway: a class, a team, a shift. Keep it plain and brief rather than warm, which is accuracy rather than pretending. Save your honesty for the moments where it changes something, and notice how much lighter you feel for not running a feud.