1. The cast talked about having an intervention for all of their puns.
When asked if the cast had any interventions that didnt make the show, Hannigan said, “We talked about needing an intervention for ourselves to stop making so many puns. We would just pun for hours and hours and hours. It was great, but we were like, We might have a problem, but we enjoyed it”. The puns all started when a guest star mentioned the magazine Cat Fancy, Hannigan added: “We started having cat puns, and we had an afternoon of punning anything about cats. Fancy that!”
2. The Cockamouse was real.
The Cockamouse was the mysterious hybrid creature that Marshall and Lily found in their apartment, and though it seems like something someone made up, like the “South Park” monster ManBearPig, it turns out this was based on a real story.” Yes, that is based on a story that happened to [producer] Kourtney Kang in New York in an apartment she lived in,” says Hannigan. She continued, “They were not sure if it was a cockroach or a mouse. And theyâ€™re pretty convinced it mustâ€™ve been both and it did fly away.”
3. Producers were worried Alyson Hannigan and Cristin Milioti looked too similar.
Hannigan says the whole process of finding the right actress to play the mom was “very secretive” and caused some suspicion around set when trailers that would “never be locked” suddenly were. Hannigan says she first met the mother, Cristin Milioti, in a makeup trailer because producers wanted to see how the pair looked side by side. “They wanted to look at us next to each other to see if they were going change her hair or something because they were a little worried that we looked similar, so I had to go stand next to her and we had some people look at us together,” she said.
4. The writers pulled from the actorsâ€™ personalities to shape their characters.
Robinâ€™s intense Canadian pride came from Cobie Smulders. Neil Patrick Harrisâ€™s skills as a magician were laced into Barney, just as Josh Radnorâ€™s intellectualism and Jason Segelâ€™s obsession with writing silly songs were woven into Ted and Marshall.
5. Barney Stinson Is a Drug Dealer from L.A. Confidential
If you were to think of films that have had a big impact on How I Met Your Mother the obvious examples would be Star Wars, The Karate Kid and Weekend at Bernies, which received multiple homages and references throughout the shows run. But the one with the biggest impact is also the subtlest. In L.A. Confidential, theres a throwaway mention of a hospital orderly who moonlights as a drug dealer called Barney Stinson. Clearly that unusual name left an impact on Thomas or Bays, leading to them turning an auxiliary character in a 1990 crime novel into a bizarre in-joke.