The Elder Scrolls: Daggerfall. One of the first PC games I ever owned. I loved fantasy as a kid and I was super excited to play something that sophisticated looking on my new computer. My sister asked what I was doing during the long (long) installation process and I was like, "you've got to see these graphics! This is what a realistic game looks like!" So she was watching as I started up the game for the first time ...
... and got pwned by the very first enemy, a Giant Rat.
My sister was a jerk and made fun of me relentlessly. It was embarrassing and remains one of my most painful memories.
Not on the same level of badness but more recently, I was playing Fallout 4 and had invaded a Synth stronghold. I'd killed everyone except the Synths behind a door I could not open. I could see them through holes in the wall but I needed to get inside to finish the mission. I ran all over the place, the floor below, the floor above, I threw explosives at the door, I hit it with melee weapons, and I raged and cursed. Thinking this was some kind of crappy puzzle or bug, I went online to see if anyone else was having the same problem.
It turned out that I simply had to go around the other side of the stairs. In a room I'd cleaned of enemies but hadn't really searched was a wide open doorway that led into a hallway that entered the locked room from the other direction. No puzzles, no bugs, nothing hidden whatsoever. I just said, "... oh," and tried to pretend none of it had ever happened.
This is why I'd never be a professional gaming writer person. I remember a long time ago when Jim Sterling was raging about a boss fight being stupid and how it would have been so much better if you could do so-and-so, then down in the comments everyone was like, "what are you talking about, you CAN do that." That would suck.
