Is it normal to have sudden spurts of deep hostility?

Sometimes I'm overcome by an overwhelming feeling of hostility: as in a need to be hostile. Its somewhat sadistic. During these instances, nothing does not frustrate me, and somehow I'm assured by my mind that arranging things so as to hamper another's (preferably immediate) satisfaction is the wondrous means to supreme gratification. In other words, being a dick to anyone around me for no real reason is suddenly very, very appealing; so much so that it takes almost everything in me to not give in to it. This is very odd if you knew me because I'm generally the passive one that's fine with close to anything.

The saving grace being that somehow I am able to identify these instances just as they take me over and so I'm able to keep it under considerable control- that is to say, the damage is kept at a minimum at least. But occasionally it does tend to spiral out of control, and when I realise this, I usually take to isolating myself. I just remain highly and easily irritable until it fades away by itself. Sometimes it has triggers, sometimes it doesn't. It isn't an equal ratio.

Conversely, I've had instances where I get insanely happy for no particular reason. As in, I could just be sitting on the bus and suddenly I have this ultimate happiness flood into me and I just want to save the world. An exaggeration- but not by much. I get really friendly, really generous, really willing. And then it dies too, and I'm left utterly confused and begging that it returns.

It sounds weird putting it down like this. I apologise for the length of it. But I had to get it out. This has confused me forever- even though I've grown somewhat accustomed to them. So I figured I'd just put it out there to see if there were any better ways around it, or if it was actually just normal (though I highly doubt that). I haven't exactly mentioned it to anyone else either because I know it sounds crazy, and its an easy association to make.

That's about it. Thank you.