The Pink Elephant
Try not to think of a pink elephant. You can't, right? Ha-ha, good laughs, chuckle for the kiddies.
WRONG.
Listen, no, listen. You have to try, as often as possible, not to think of a pink elephant. Your brain makes the image as you think the words. Good. That's good. That's safe.
If you find you suddenly can, if you realize you are idly thinking about anything except a pink elephant and unable to recall what you were supposed to avoid thinking about, run.
That means it's trying to hide from you. That means it knows that you know. That means it's coming.