People become careless around someone they believe they have figured out.

Once someone is confident they understand you, they stop paying attention. They stop preparing, they make assumptions, and they speak more freely because they think they already know how you will respond. That carelessness is created by their certainty rather than by anything you do. Correcting it usually costs more than it gains.

When you notice someone has you comfortably categorised, resist the urge to complicate their picture. Let it stand and use the room it gives you. Being underestimated is a resource that disappears the moment you spend it on recognition.