This happens because this fortuneteller is worshiping the Jinn and they get in touch with your Jinn and ask his about things that took place in the past in your life. As for the things in the future, the Prophet salla Allahu alaihi wa sallam told us that the Jinn climb up to the lower heaven where they listen to the angles and may take a word or two before they are thrown with meteoroids or a shooting star. They then give it to the fortuneteller who adds to it 99 lies.