Sam Winchester was born in the year of 1983. When Sam turned 6 months old, something odd yet life defining happened. The yellow-eyed demon by the name of Azazel poured some of his blood into Sam's mouth. This was how Mary Winchester, the mother of Sam and Dean, died. She walked in on Azazel and Azazel killed her, burned her alive. But that was nearly 30 years ago. Sam is 23 now and Dean is 27. The incident lead John Winchester into the intense desire to hunt down and kill what killed his beloved wife, and so he raised his boys to become hunters, to kill the things that go bump in the night.
What the boys found out was that Sam had powers, visions, caused by the demon blood of Azazel. They gave him vivid nightmares, the visions did. But these visions lead him to stopping deaths before they could happen. Most importantly, they could also lead him to others like him. Yes! There were more like him. Part of him found it reassuring.
These other people mostly had similar psychic abilities to Sam. Some of the powers the boys had observed included mind control or influence, visions, even some guy could kill whoever he touched. You, however, had empathic abilities. You could feel other peoples feelings and emotions and if you focused hard enough you'd be able to manipulate and change other peoples emotions.
Sam and Dean were staying at an old motel, it had been a long night and so they were getting rest, sleeping soundly... That was until Sam woke up in a fit of cold-sweat. A vision - The vision was about someone getting hit by a car. How simple for one of Sam's visions. But if it appeared in his vision it must be important.
"Dean- Dean, wake up. We need to go." Sam awoke a grumpy Dean and got dressed and soon they hit the road, travelling to the town from his vision.
"So let me get this straight. You see this- this person, in your 'vision' and they get hit by a car? Seriously?" Dean complained. They were stood on a sidewalk. "A car?"
"There- that's them." Sam said, pointing to you, walking nearby.