Yoga says instinct is a trace of an old experience that has been repeated many times and the impressions have sunk down to the bottom of the mental lake. Although they go down, they aren’t completely erased. Don’t think you ever forget anything. All experiences are stored in the chittam; and, when the proper atmosphere is created, they come to the surface again. When we do something several times it forms a habit. Continue with that habit for a long time, and it becomes your character. Continue with that character and eventually, perhaps in another life, it comes up as instinct.