WHY NEGATIVITY?

Where's the logic in chosing negative over positive? Don't people ask themselves why they do things the way they do it anymore?




Here's something I can't quite get a grasp of: Why do most people prefer the negative aspect of things?
Examples:
1. Why do people prefer to immerse themselves in sorrow when they have a lot of blissful memories to smile upon?
2. Why do people feel jealousy for people they love instead of being happy for them?
3. Why do people love to listen to sentimental music just to find themselves teary-eyed after?
4. Why do people still keep memorable things of someone they lost?

I mean, What's up with that? Isn't this as ironic as a parent saying, "I'm doing this because I love you", while sadistically beating up his/her child? I know that we cannot appreciate light if it weren't for darkness, but man! Chosing darkness, now that's different! Wouldn't the world be a happier place if everyone just chose to be happy?

As Helen Keller once said, "Keep your face to the sunshine and you cannot see the shadows".