Lemme put this out there. There is no such thing as a "perfect person". Such a power would grant massive abilities, the temptation of which would be too much for a person not to use for some personal gain. We would have seen such an individual at some point in time.
Now, what I do believe is that there are many kinds of geniuses. There are some people who can just look at a piano and start to play. There are others that see mathematical problems in their heads and can solve them instantly. Some people are extraordinarily intuitive when it comes to people--they just have a Dr. House-like ability to read the microclusters of twitches, verbal queues and inflections to gain an insight to what a person is really thinking. Then there are those who just have a strong intuition for calculating odds and landing on the right one enough to make it look like prescience.
Those people aren't always right: we're humans after all and not perfect. But they end up being right about enough things to really knock the socks off the people around them.