I feel like I'm very easily overstimulated. It can start from conversations (high pitch voices - person I'm talking to gets super excited when we're talking), too many people talking to me at once (even if 2 people are trying to talk to me at once, I FREAK out)
Loud music throws me into overdrive/overstimulation - which generally starts in a positive environment, but almost always throws me into a negative. bright lights, loud noises, etc.

All in all over-stimulation causes mania or the other way around - I don't know which occurs first since it feels like it happens so fast. I get overly stimulated almost always in "positive" settings/surroundings and get really hyper (there was a period when I would randomly jump on couches and beds.. ), loud, head spins, get the "third person view" - literally feel like I'm high (sometimes I wonder if I am.. ) But it doesn't take long for it to get ugly; something so insignificant can piss me off (someone's constant pessimism, sarcasm) and I get extremely agitated, overly anxious, even get paranoid. and just straight up CRABBY! Loud noises irk me and throw me over board, making me even more angry/snappy.
I would think that when I'm drunk it would be waaay worse, but surprisingly alcohol does the opposite for me when it comes to over stimulating...