Is it just a brain malfunction?

Anger... It's a pretty confusing, yet fascinating emotion. Anger wells up from annoyance which can come from a huge variety of sources. If you let your annoyance blossom and ripen, it would turn into full blown anger. In return, the people around you feel uncomfortable, and sometimes even hurt by your reaction to whatever it was that annoyed you in the first place.
Where does it all come from? What happened in the past that placed that trigger in our lives? The trigger that some might call "a hair trigger" because it is so easily pulled.
Is everyone like that? Or are their some on this Earth who actually let the things that would normally annoy me just pass them by and forget about it?

Yeah... a pretty interesting subject.

I know this guy who has a sister-in-law with a brand new boyfriend... well, relatively new I guess. I am told that this guy that I am talking about here has a child and whenever this boyfriend is around with the sister-in-law he gravitates towards this guy's child and like automatically starts to play with this child. Ok, that's not so weird I guess, but I'm told that when the boyfriend plays with this child that he always is putting his hand on the child's back and rubbing the childs back and that type of thing.
Getting to the point... I am also told that this behaviour makes this guy extremely annoyed to the point of wanting to punch this boyfriend's face off. I mean, come on. He says that everyone else thinks nothing of the behaviour so he feels that he might be being irrational.

WHAT placed this man's anger within him? Why does he get angry at such a thing? This is just one example of something that may annoy another person... it's a real life story, which makes it even better as an example.

One day anger flares up at something that the day before did nothing. Incredible.... Why though? Why is it like this with emotions... so unstable and unreliable, yet God placed them within us to use and control for His glory.

God, help us.