Tale of a sorry end to a good run

I was having a great run with a mage. Found a leather armor +2, whip of shocking +2, a couple of rings and a good selection of wands, some even upgraded.

I was dominating level 13 in the caves. There, I found a treasure room with the pool and the piranhas. I readily gulped down my only invisibility potion and went for the treasure, hoping for a scale armor. I had saved 2 or 3 scrolls of upgrade and a couple of arcane styli waiting for the right armor to appear.

As I was making my way to the treasure chest, a gnoll brute and a gnoll shaman both entered the room. Trying to avoid them, I took too long to get back. Through bad luck and miscalculation, the potion ran out one step from the door, which was blocked by the brute.

So, I found myself facing three giant piranhas and two gnolls. I didn't have a teleport spell, and my stones of blink were useless as I was surrounded. I tried everything I could think of, and downed 11 (!) potions of healing and shielding, but I was taking too much damage. In the end, the mage succumbed to his wounds and the game was over.

I exited the game in frustration and swore not to try again in at least a week (not for the first time).

Five minutes later, to my horror, I realized I forgot that I had a seed of fadeleaf that might have saved me :-(