"I'm a Dork" Department

In England, people flash their brights to signal a variety of things, not all of which are discernable to me. But I have figured out that a flash can mean "I'm letting you go" or "Thank you for letting me go" and can even take the place of a punitive honk. Without fail, every time I attempt to thank someone for letting me pass, I turn on my front and back windshield wipers instead.