A customer yelling at you over fries is having a bad day. It isn’t a review of who you are.

Somebody’s anger usually arrives already full, and you happen to be standing where it lands. What is being shouted about is rarely the real subject, which is why nothing you say improves it. Taking it as feedback gives a stranger’s worst ten minutes authority over how you see yourself. That was a transaction, not an assessment.

Stay polite, fix what you can, and let the rest belong to them. Afterward, say one accurate sentence to yourself about what actually happened. Then get on with the shift instead of replaying it all evening.