Why do manipulative people still get under my skin at work?

You handle the ordinary day well enough. A late report, a disagreeable client, a tight deadline — these you meet without much trouble. Then someone raises their voice, or twists your words, or smiles while working against you. Something in you tightens. You leave the room replaying it, angry at them, angrier at yourself. Here is what you are missing. You have trained yourself to manage situations. You have not trained yourself to manage a certain kind of person. This one is not trying to solve a problem with you. They are trying to win something at your expense. That calls for a different skill. Not more patience. You cannot control whether they raise their voice or bend the truth. You can control what you treat as information and what you treat as bait. Most of what rattles you is bait. Learn to see it as such, and it loses its grip before it ever reaches you. If what you face crosses into real threats or abuse, this is no longer a private discipline — bring in someone with authority to act.