People that expect you to do bad...
...and they end up doing bad instead of you. Not saying this is always the case, but some people can't see the forest for the trees. They see you pick something off meta and immediately "YOLO ALERT R%%%%% TROLL GG ILL PICK SOMETHING SOOPER ON META SO THIS TROLL DOESN'T MAKE US LOOSE!" and they end up feeding off the bat while you dominate your lane.
Not every off meta pick's purpose is to troll. Sometimes it's not what youre playing, but simply how good you are at playing the game and/or the champion.
I'd be interested in hearing you guys' stories about someone expecting you to fail, but you end up succeeding while they ended up failing in the place they put you in :D
varus jungle at low levels, I was happy it worked but sad that I didn't get a leash because I was "baisically useless" or "not playing varus right." Also im only level 13.