Forgetting to switch from your EES or Regen gear when you re-enter vs 3 EPs. (also half cut and just woke up)
Drunk in a group vs the last set of Four Corners being the only Tank / Healer and using the old "Right Click" method and going to the toilet without telling the group and you come back and dead... oh well, had another Guardian that rejoined group to complete run.
Oh, only 3 pixels and I will kill this EP in one hit, letting my own hit points go down to like 800 and I hit low and EP crits me.
Forgetting to Exit to town when you go to answer the door (again intoxicated) vs EPs and the person at the door keeps you their too long.
Of course lag, had this happen a few times and the pool is 2k+ (50-60% HP bar) but the gear is mediocre and boom... you get quad critical hit and die. (you can see them hitting you, but your character is doing nothing and all you see are the massive attack lines... this lag sucks as you are still trying to exit cata).
Power outage at the wrong time ... return to game... dead (before some updates)
Complacency ... having great gear and too overconfident and boom (level 87 at the time) and you get the Bash vs 3 EPs and they are multi critting you in that one action.
Game is easy, 80% of my deaths were my fault ... drinking, getting distracted by outside influences, damn I even remember joining the party and leaving my character facing off monsters and forgot I was playing the game. But it is a game, I am still here and still playing. I like this game, love HC because of it.
... hence I play solo in my time.