THINK before you are thought. If you will not THINK, someone else will THINK on your behalf. But that someone else will not THINK, what you should THINK, he will THINK, what he wants you to THINK and in this whole process, you will loose track of your own thought.
So there is no harm in THINKing, as long as it is for the sake of knowing the purpose of you being alive, as a human.
Because it is only you, among all the living species of His creation, who has been bestowed upon, with a beautiful gift, called MIND.