Mando fever! ;]
I love it when you get an instrument and you pour the love into it, and then all the sudden it sounds like something, ringing like a bell, and then only getting better from there.
Weird thing is everything could be up to snuff when you're done but it still kinda sounds like rat poop, constantly needing retuning, etc, this could go on for days, and then suddenly, it just kinda pulls out of it and starts sounding good, age old cobwebs finally clearing away.