Noticing what? Noticing how you slip into the jiva suit (your illusory identity, the narrative/story/voice in the head that claims it is you, that x,y, and z is a problem and until it gets sorted out you can’t possibly be happy/at peace, etc.) without realizing it. This fear based mind made entity is not you. As Eckhart Tolle says, “You are not the voice in the head, but the one who hears it.”
But Eckhart’s pointer is of no benefit until you see/notice IN YOUR OWN EXPERIENCE what he is saying. In other words, are you your thoughts or do you have thoughts? There is a world of difference between having something and being something. If you believe you are your thoughts, then you have to suffer because every thought is a limitation, and thus not what you truly are.
The thing about noticing is that you have to actually do it. Just reading about or thinking it sounds like a good idea won’t yield its amazing fruits. You have to actually do it, as in notice (and, imo, you cannot notice too much or too often) that there is no hope for the jiva as its death is certain. This is the fact that the jiva doesn’t want to look at head on. However, what if it’s noticed that you are not the jiva and never have been? And once you notice this you keep on noticing until it becomes more and more your direct experience.
p.s. You can get more info or RSVP here: