I happen to be moving out of an apartment complex where one of the neighbors is exactly like yours.
For my [just about ex-] picky neighbor, it was whenever I'd watch a DVD. I never had the volume louder than conversation level, yet this neighbor would go all out about how my "stereo is too loud"... and follow it up with the loudest cartoon-esk sneezing you've ever heard. "EGH--hoo... EGH--hoo... volume too loud! ... EGH-hoo..."
Ugh. As glad as I am that I moved in there, I am so glad I'm moving out just because of that neighbor...
Cheaper rent for a bigger apartment, moving in with my fiance &c are good reasons to be happy about moving too, of course .