Respect the person across from you. Underestimating them is the fastest way to lose to them.

Contempt makes you careless. The moment you decide somebody is not a threat you stop preparing, stop listening and start assuming you know what they will do, and that is precisely when they do something you did not plan for. Taking an opponent seriously is not flattery. It is the only way to stay accurate about what is in front of you.

Before your next match, debate or difficult conversation, list two things the other person is genuinely good at. Prepare for those rather than for the version of them in your head. You will be readier, and you will be less surprised, which is most of the advantage.