Why do people Piss and Moan?

It's not like she bitches all the time or anything thank God (I'da been gone so long ago nobody would remember what I even looked like.)
Well if she dont do it all the time then I take back what I said, she is just being bitchy is all and everyone has to every now and again. Some more than others. I, personally could be shittin rainbows and you would find me bitchin about how there isnt enough contrast between the colors lol! I'm a bitchy person.

Get what I mean?