RNG
I can't stand RNG! There's nothing I can do, no amount of training or preparing to combat RNG - it just happens as the Universe wills it, by chance - and I HATE it.
And, when the RNG is, let's say 2% on some loot (that it drops), and I fight 300 some odd creatures and it STILL hasn't dropped! Like, really, I'm supposed to be getting this loot one out of every 50 and I'm over 6 times that and I still haven't seen a one!
Like, c'mon!
I'm gettin' tired ova here!