I've always found that these "Quick, don't think of 'x'" things are a silly example. You end up thinking of X the moment you read X, just before it gets put in

I've always found that these "Quick, don't think of 'x'" things are a silly example. You end up thinking of X the moment you read X, just before it gets put in context of "not" and "think". It's like telling the parser not to tokenize a given word. Then there's automaticity, which you have to turn off, which is made harder by "Quick", further setting you up to think further of elephants till you get around to grasping the meaning of the phrase.