How I Met Your Mother featured an Easter egg that connected Zoey Pierson to the series three seasons before she was introduced. Zoey was a recurring character in How I Met Your Mother season 6, starting out as Ted's enemy for protesting the destruction of The Arcadian, a historic hotel in NYC that also happened to be where Ted's new project was being built. Over time, their hatred for one another transformed into a friendship, and eventually a romantic relationship. Zoey was married to The Captain and even after they separated, Ted felt like the "bad guy" in the situation. Ultimately, though, Ted and Zoey's relationship couldn't survive the arguments and disagreements surrounding the Arcadian project so they later broke up.
During How I Met Your Mother season 6, Zoey was seen wearing a wishbone necklace that might have been familiar to viewers: that necklace was the same exact piece of jewelry that Lily wore in the pilot episode in 2005. Some viewers could think that it was just a coincidence or a styling department decision. but there was actually an in-universe reasoning behind the reappearance of the necklace. The explanation of how Zoey got the necklace came How I Met Your Mother season 3, years Morrison joined the show.
Related: How I Met Your Mother: What Happened To Ted's Cowboy Boots
In the season 3 episode, "Everything Must Go," Marshall and Lily learned that they needed to find $1,500 to fix the slanted floor in their apartment. To acquire the bulk of the money, Marshall suggested that Lily sell some of her designer clothes on a website called lilyandmarshallselltheirstuff.com, but she wasn't too pleased with that idea. Rather than let some of her clothes go, Lily decided to sell some of her paintings. And it turned out that Lily had more fans of her art than first thought.
When Zoey began to become friends with the gang, she revealed that she was a fan of Lily's and even bought some of her paintings. Although not explicitly stated, it seems very likely that Lily gave into Marshall's requests and offered some of her personal belongings on the website, including jewelry: when Zoey purchased the art, she may have also bought the easily identifiable wishbone necklace.
How I Met Your Mother was an expert when it came to continuity and featuring long-running jokes throughout its nine-season run. It would take fans of the series multiple viewings to catch all of the Easter eggs and witty references. For that reason, the series never gets old.