Due editing, a lot of mind games Disney and the EP's are trying to play. Personally I think it's crazy the amount of force strength Rey already has, Anakin wasn't even that strong after years of training, and he was generally thought to have unlimited potential, and quite possibly the most "force sensitive" in the Star Wars Universe. So long as the film is good, not an Empire copy, and Rey ends up being a Skywalker: I'll be happy I suppose.