Understanding that your instincts, no matter how strong they are, can be, and in fact, often are; completely wrong.
I am going to change the word instincts to intuition.
Instincts are seldom wrong. They have been developed over eons.
Do you question your instinct to quickly pull your hand back when you touch a hot stove?
Intuition, on the other hand, is getting the answer from somewhere other than your mind.
Intuition can be practised and increased. And it can give answers to seemingly impossible questions in an instant.
Most science types poo-poo intuition, right up until they start to develop it themselves. Then you start getting answers and see the results of interpreting and applying those answers. It really changes your life.
Then you notice the gulf between what you think you know and the sea of information you have a peep-hole into.