1. Zoey wears the necklace Lily wore in season 1.
2. In just one scene, we see that the couple in the background spend a lifetime.
3. In Barney’s return to Moscow in 1807, he drinks ‘White Russian’ and James ‘Black Russian.’
4. Sometimes HIMYM puts up-to-date advertisements on older episodes. For example, in this episode published in December 2012, it has the ad ‘Why Him?’ (Why He?).
5. In the episode where Marshall lost his father, there is a secret countdown until we get the news.
6. Conan O’Brien was an extra at MacLaren’s pub once, and he didn’t have a single line.
7. The clock at Lily and Marshall’s House is always 4:20.
8. The boy who played Lily’s cousin in the episode “How Lily Stole Christmas” played Barney’s fake son in the episode “The Stinsons.”
9. In “Disaster Averted,” he says he kept the last slap he gave to Marshall Barney on a rainy day. “End of the Aisle,” in the episode where he gave Barney the last slap, is raining.
10. Barney’s role in the episode “Stuff” is called “Suck it, Lily.”
11. The club Ted went to on St. Patriarch’s day is called ‘Low Point,’ which is a reference to Ted’s current mode.
12. In season 4, in the episode “Murtaugh,” Barney wears a tie even while going to the party.
13. Even Barney’s Christmas tree is decorated with ties.
14. Again, in the section called “Murtaugh,” a child spits in the face of the other child who pushes him to slide sideways.
15. Robin’s space show in ‘Space Teens’ old show is a curling stone.
16. In the episode “Mom and Dad” in Season 9, a Rastafarianism flying a glider eats a ‘sandwich.”
17. This sign that says” DUK TAI ” is a reference to Barney’s duck tie.
18. In the episode they jump into the future in 2029, the headline on the back of the newspaper is that Marshall has captured the Loch Ness Monster.
19. Look who’s in the background in this photo of Tracy and Louis.
20. According to their suitcases, all of these women slept with Barney.
21. This tombstone with ‘Mother’ written on it may indicate the end of the series.
