I don't have anything epic, more so, extremely frustrating.
In the original Pokemon Blue, i was hunting for Mewtwo. When you're 6, this is quite awesome, as well, you don't know how to play properly. However, i was the youngest brother, so this game was my Brother's, so i had to make sure he didn't know i was playing HIS game.
I lacked both medicine and high leveled pokemon, ranging around LVL 50. So i went into the Unknown Dungeon and figured out that my ass was getting kicked. Marowak's weren't very easy, since my Blastiose fainted quite quickly, and Ditto's need to suck a cock. F**k those assholes.
At the point in which i could surf to Mewtwo's island, i had 2 pokemen left, both very weak, considering my lack of medicine. I thought, "Screw that. I've got a Master Ball", un-duplicated, unfortunately. So i swam over to his island, and fought him, Saving before the battle.
I thought that maybe i should've weakened him down. I can't remember now, but i think if you throw a ball at him without weakening him, he won't be caught, regardless of ball. I tried Blizzard from Articuno, which both went second as well as missed. Thank God Mewtwo used Barrier. Unfortunately, he thought against his stupid move and considered Psychic, fainting my bird. Thank God i still had Alakazam.
So i rushed to use Psychic on him, which although went second, dealt some damage. However, Alakazam had very few points of HP, and so i had to catch him right now. Not only that, my batteries were dying. I opened my inventory, and selected my Master Ball. And then...
The "Your BOX is too full" message popped up. At that point, i started to cry. Not only was i not able to catch it, but my brother was probably going to kill me, literally. I turned the game off, and then remembered, "NO! I SAVED RIGHT BEFORE HIM!"
Then, i got punched a couple of times, and never played his game again. Until 4 years from then, when he didn't care