At the moment, you can't predict the future state of my brain for more than one reason, one of which is that you don't have much information about the current state (precise information anyway, you may have an opinion about the average state).
Do we not literally predicate our friendships and relationships on being able to predict the future states of minds? How long do you stay friends with the person who randomly shows up or doesn't, to any event you invite them to? Or whose tastes vary unpredictably from day to day, giving you no framework to contextualize them?
(No it isn't)
It also implies that we might life this life over and over forever.