28/08/2012 06:56 BST | Updated 28/08/2012 07:33 BST

David Armand Stars In 'Sammy MacFarlane: Doing The Knowledge' (VIDEO)

You know how every time you learn something new, it pushes something you used to know out of your brain? (What's that? You didn't know that? It must have been pushed out of your brain.)

Anyway, this hilarious new sketch, starring and co-written by David Armand, demonstrates the clear effect this memory loss can have on a man when he's training to be a London black cab driver.

Oh, and before we forget, we should also name-check director Adam Jenkins, plus David's co-writer Nick Tanner and co-stars Martha Howe-Douglas and Justin Edwards. Good work, everyone!

Can't remember what you were supposed to be doing next? Ah, don't worry about it. It probably wasn't very important anyway. Have a look at our 10 favourite hilarious viral videos of last week instead...