check out the following exercise, guaranteed to raise an eyebrow. there's no trick or surprise. just follow these instructions, and answer the questions one at a time again, as quickly as you can but don't advance until you've done each of them...
what is:
now repeat saying the number 6 to yourself as fast as you can
for 15 seconds.
then scroll down.
quick! think of a vegetable! then arrow down.
you're thinking of a carrot, right?
if not, you're among the 2% of the population whose minds are different enough to think of something else. 98% of people will answer with carrot when given this exercise.