Postman Pat

Postman Pat is a British children's television show that first aired on September 16th 1981 and ran until March 29th 2017. Though there was no specific date that the meme started as Bigdabber and potentially other members used to watch it when they were young, the show wouldn't become much of a meme until the late Post-retirement arc.

Meme History
Most memes so far aren't even from the show itself, but instead from the DS games. (yes, really)