Oh, if we're doing one of these threads, my white whale is a mid-80's CGA DOS game where you set off in search of a lost ... uncle? and have to solve puzzles and avoid hazards.
There are two parts I remember very clearly. The first is that you have the choice when you leave the house at the beginning of either bringing along a walking stick or something else, and if you don't choose the stick, there's a part on an outdoor trail where you twist your ankle and lose the game.
The other part I remember is getting shrunk somehow and ending up in a drawer full of drinking straws. You have to work your way through this tube maze, but some of the straws are clear (invisible) and if you wander into one accidentally, the game lets you know it was so narrow that you get stuck in it forever, lose the game, and die.