I *hate* sudden loud noises!  But I agree, it's a pain when people assume things which aren't true.  I can't tell you the number of times I've been accused of being "slow" or an idiot, to my face and behind my back, simply because I'm quiet and prefer not to join in a conversation that's not work-related.  They seem to equate "won't" with "can't", which is not the case.  My lack of interest in their lives outside the workplace is no indication of my level of intelligence.  It may say something about my taste, but not about my IQ!
Alison