New today Trivia: When the gang are in a taxi on their way to one of the burger joints with a green door and a red neon sign, look closely at Cobie Smulders' eyes whilst Barney is talking to Lily about Goliath National Bank - she is almost falling asleep when her character is not meant to be sleepy. Watch as her eyes widen, desperately trying to stay awake.
Trivia: When Ted and Robin are at the restaurant, they are accidentally sent a champagne glass with an engagement ring in. A man then claims the ring and proposes to his girlfriend. This couple really did get engaged on the show - the guy set up the surprise proposal, as his girlfriend thought they were just there as extras.
Trivia: Chris Elliott plays Mickey Aldrin, father of Lily Aldrin (Alyson Hannigan). In real life, Elliott is only 14 years older than Hannigan.