I learned all this from a room mate I had in college. They’re so deeply insecure and so desperate to impress other people, that they’re extremely gullible and easy to manipulate, once you figure out the kinds of things they want to hear, and just constantly reassure them that you believe it! I’ve been able to get my way on occasion (and have an easier time of it) by listening carefully to such people, and then simply repeating back to them what they tell me about themselves, and it often works.