This is one of those maxims that I am not quite sure I agree with because one never knows where the instincts are coming from. If your instincts are coming from something designed to fulfill your subconscious expectations of who you think you are supposed to be, then those instincts are not necessarily beneficial and can move you toward something that would hinder you. If they are coming from your higher Self, then they can lead you toward something beneficial to help you grow and expand your mind.
Before you come to a place of instinctual responses, take a moment to question. Where are they coming from? What are you going through? We often end up saying that our instincts were right. Is that the truth, or just a rationalization and justification for the outcome of things? Did your instincts truly help you or hinder you? It is always good to question.