Some people don't know how to talk

They treat discussions like a competition, instead of a mutual clarification
If you ask the definition of something they go "hah! you don't know this? then you're a noob and I'm obviously more knowledgeable than you, and thus I have won! now shoo", when maybe you just want to know what is their definition, to compare with yours and clarify what might be your and his misunderstanding

>>5
It's pretty obvious. Have you had discussions with most people?

I can manage to get anyone to accept pretty much anything I say by just saying it the right way. Few people actually listen to what you say, most pay attention to the way it is said and whether they like how you present it.