You walk into a room and this girl looks at you, your brain tells you that she's has made eye contact with you because she likes you. Instead she hasn't its simply that your eyes met. Your brain tells you she's into you when really she isn't. If you thought rationally you'd probably realise that it was just a coincidence, but your brain has said "Mate you look damn good, of course that lass fancies you!"
Something like that D-boy?