When a league of legends player has a hard time enjoying games different from league of legends.
Often happens to player who are very competitive, And different games of different difficulties tend to be too little of a challenge. Of course some times the difficulty is unrelated and even the hardest game , Will still be considered easy compared to the likelihood of over-topping another player online.
Jon: "Oh dude you should play this new "Title" That is coming out, It looks sick!
Bob: "No thanks man I'm just gonna league"
Jon: "But dude , All you do is play league"
Bob: "What can I say , Single player games are too easy"
Jon: "Bob I think you might be suffering from "League poisoning"