I've met a lot of average every day people that have claimed to be precognative. Then we also have people like Nostradomus and Edgar Cayce and rasputin. Basically I think there is some truth to it but its not something that can be fully understood or accurate. Most logical thinking people will chalk up certain incidence on keen intuitive abilities (understanding probability).
Then there are the people that are just insanely good at body language etc and will use that to make a living.
About 90% of them are scams and nonsense but the power does exist but it's one I'll never get involved with ever. Anyone who does legitimately have that ability make no mistake has most likely literally made a deal with the devil that power is demonic. And in no way should you get involved with it.