Some of the greatest films ever made do not enjoy much success on the home video market. They don't have diehard fan bases that can quote the movie verbatim. And they certainly don't inspire viewing parties with all your friends and a big tub of popcorn.
Because, while they may be remarkable, downright essential pieces of filmmaking, they're also much too harrowing and soul-crushing to sit through more than once. In fact, watching these cinematic achievements again would be a sadistic exercise in self-torture.
These are the kinds of viewing experiences so devastating that you have to take a shower immediately afterwards just to try and wash away the agony. But no matter how hard you try, you won't be able to wipe them from your brain. So just why in the hell would you want to put yourself through that again?
Now, that's not to say all generally sad movies need to be locked away after the first viewing. No, to truly be unwatchable a second time they need to be top-to-bottom bleak, tragic, depressing, disturbing, or some combination of the four.
And don't you worry, every movie on this list nails that quota. Hard.
Just as a note, all horror movies have been purposely left out, as there would have to be an entirely separate article dedicated to the many films in that genre too sickening to watch a second time.