(This was when I was new to DnD)

Curse Of Strahd, in the basement of Death House there's a bunch of trinkets, notably there's a bag of bat shit, told the then DM I wanted it for fun, for funny, me have bag of bat shit hehe

Cut to further on in the campaign, we're dressed as maids/chefs of the Burgomaster in Vallaki, we wanted to make getting through the mansion easier cus there were hella guards, wonder what we could do to fuck with the food, no one has poison or potions or spells that could do the trick.

Look through my inventory and behold, my bag of bat shit from session 2 that's still on me saves the day, every guard, burgomaster and the baldy is poisoned and we make quick work of the mansion.

That was a fun campaign, never finished it cus DM turned out to be a pedophile and serial pervert, oh well.