A new How I Met Your Mother theory about Lily has just been revealed to be true by its co-creator.

Last week, it was highlighted that the sitcom continually pointed to the fact that Lily – the character played by Alyson Hannigan – had a very famous relative. Namely, the astronaut Buzz Aldrin.

The Reddit theory goes that Aldrin was the father of Lily’s mother. The most striking piece of evidence suggesting this is the fact the pair share surnames and that her maternal grandfather was one of Lily’s few family members that never appeared on the show.

One of the family members we do meet, though, is Lily’s grandmother, Lois.

Intriguingly, Buzz Aldrin was married to Lois Driggs Cannon from 1988 to 2012, which would make Lois Lily’s step-grandmother considering Buzz Aldrin’s first wife, Joan Ann Archer, gave him a daughter named Janice – the same name as Lily’s mother in the show.

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At one stage in the series, Lois states that her husband served in the Korean War, which Buzz Aldrin was a fighter pilot in before he began working for NASA.

For those who are wondering why Lily wouldn’t have taken her father’s name over her mother’s, it’s suggested that creators Carter Bays and Craig Thomas regularly pointed out that Lily’s mother was a staunch feminist to make it more likely she wanted her daughter to have her surname.

Backing this up is the fact that Lily didn’t want to take Marshall’s surname when they eventually got married.

It turns out that the fan who picked up on all these points did so for good reason – Thomas himself confirmed that Lily was intended to be related to the astronaut.