Positive Exchange

Chances are, if you are cut off by an angry driver, you'll be ticked off. You get yelled at for being in the way, and you'll want to shout right back. If you're listening to incessant complaining, you'll probably be tempted to pitch in your own woes (It's important to remember that sadness is not a competition). Before you know it, the discontent you encounter on a daily basis affects your mood and effectively ruins your day. You won't be able to help spreading it to others after that.

Negativity breeds negativity. It can't be helped.   When you allow negative attitudes a part in your space, they have a high chance of overrunning your mood. But there's another side to that coin: A positive attitude behaves the same.

I find that when a friend has nothing good to say, it's best to stay away. That sounds harsh, but being in a pissy mood is not something I am a fan of. I love being around people who will marvel at the way how clear the sky is rather than moan over the cold. There is something invigorating about people who smile at the rain, laugh when they slip on the sidewalk, and tell you strange, quirky stories about nothing in particular. 

I'm not talking out people who bury their problems. That is unhealthy, and I would never ask anyone to do that. Still, when small problems with easy solutions are drawn out to tiresome odysseys, I get bored. I get tired. There is little more exhausting than being around a person who has nothing better to do than explain to you in detail how awful every moment of their existence is. 

But there is more to being a little happier than keeping happy people around you. You have to infect others with your positive energy. Go out of your way to smile at a stranger, sincerely ask a store clerk how they are. Even if you are unhappy, you don't have to spread it. Besides, doesn't making someone happy at least coax a small smile out of you?

Happiness seems to work on an law similar to equivalent-exchange. It's pretty simple. Show happiness and you'll receive it.