Go the whole match thinking your teammates are awesome. They make calls, they listen to calls, they roam and ward and play really well... and then they either bash the enemy team calling them trash or spam 'ggez'. It is pretty disappointing. My opinion of them goes from "Man, I hope to get more teammates like that" to "Oh... turns out you are assholes. Cool."
It is not that hard to win and not be a dick about it. I have been doing it for 5 fucking years.