I'm not psychic by any means, but I am empathetic. It's not that I can always tell what other people feel, but I almost always feel what they feel to some level.
I think we're all born with this ability, but learn to tune it out as we get older. If you watch small children, they laugh when other children laugh and they cry when other children cry, even if they don't know what they're laughing at or crying about. As we get older, these empathetic feelings get in the way of whatever we're trying to do or whatever we're trying to feel so we learn to block them out. They're still there though, always there.
The problem is that most of the time other people feel angry or annoyed or frightened or distracted and almost always lonely. Feeling those emotions of your own is bad enough, but when you share them from the people you encounter, it can become quite a burden.
It can be such a burden, that sometimes I prefer not to be around anyone at all. Feeling nothing but my own thoughts and my own emotions, although quite lonesome at times, is often better than sharing the suffering from the rest of the world.
A friend once suggested that I surround myself with happy, successful people and then I wouldn't mind sharing their empathetic experience. There problem there is that most happy, successful people don't usually feel that way, and if they do, they're often almost completely empty inside.
There is a payoff though. People do sometimes feel joy, love, laughter and beauty. Sharing these emotions with them can be a privilege. These things are valuable though because they're rare, and sometimes it can be a long dry patch between bright moments.
Sometimes I meet people whose need to share what they're experiencing is so great, that being around them almost crushes me. I let them do it though because I can feel how badly they need to share their experience, but it's pretty draining, and afterward I usually need sometime alone to recharge.
John Donne said "No man is an island", but he's wrong. All men are an island. We're close enough to signal each other and exchange goods, but ultimately we have to isolate ourselves to keep any identity at all.