The hard part is telling it apart from anxiety, since both arrive as a feeling with no argument attached.
They have different textures, though. Anxiety is loud, repeats itself, gets worse the more you examine it, and has a habit of turning up at two in the morning specifically. Intuition tends to be quiet, says the thing once, and doesn't mind being checked. Someone who has driven the same road for fifteen years lifts off the accelerator a second before they could tell you why.
That quietness is what makes it so easy to overrule. Worth learning the sound of it, because it's built out of every situation you have ever been in, and it is considerably faster than you are.