Imagine we are all scientists; researching for something. Each individual is trying to present his/her every foundings. That roughly translates to excitment.This massive feeling when you are about to make a breakthrough, either a materialistic one or just ideal. Both serve the same purpose - Evolution.
Imagine a serial killer. A cold-hearted person with computered-like characteristics. This individual is born like this, and he has a single purpose; to challenge our intelligence. It seems like a test of nature, have we adapted and reached the next level ? Have we not ?
The Fields on which we can evolve are infinite. Infinite like our imagination. We either choose what we want to delve into - or it chooses us, nontheless we struggle to overcome each puzzle every time.
Dedication is crucial and natural-born for what each and every one of us is destined for. But, is it enough ? Sometimes, clashing our wills against each other is motivational enough to reach a new state of existance. This is exactly what makes you feel happiness - Evolving.