1. Because of things like this.
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2. Because of how Marshall totally stole the show, even when he was in the background.
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3. Because of how they cover up the "holes" in Ted's memory.
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4. Because of this callback.
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5. Because The Mother's name was actually revealed way back in Episode 9 in the first season.
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6. Because of this cunning use of colour theory.
7. Because of how precisely clothes were matched.
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8. Because there's no situation when a high five isn't relevant.
9. Because Dr X's website actually exists.
10. Because "before a man meets the woman he'll marry, he'll make one final, horrible mistake."
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11. Because Robin Sparkles' spaceship was also a curling stone, because Canada.
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12. Because even in the first shots of the Hoser Hut, there's Paul Shaffer.
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13. Because of this perfect background joke.
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14. Because Marshall's jacket actually reappears.
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15. Because this Rastafarian is eating a "sandwich".
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16. Because whenever Marshall went on a trip, he brought back beer – even in Marvin's stroller.
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17. Because the red car case that Robin's locket is in has been there the whole damn time.
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18. Because this motorcycles sign was in an episode way before Barney actually did something that caused it to exist.
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No word on the llamas, though.
19. Because they eventually found all the doppelgangers.
20. Because of how the Van Smoot dynasty was so carefully worked into the show.
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21. Because Robin kept her promise.
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22. Because Barney really, really does use 83 whenever he's making up a statistic.
23. Because of how Barney's advice was truer than he ever expected.
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24. Because of this symmetry between the start and the end of the show.
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25. Because there really are a lot of similarities between the mother and the daughter.
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26. Because Ted and Tracey both love coins, so they named their daughter Penny.
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27. Because of this bit of foreshadowing.
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28. And how this more or less came to pass.
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29. And maybe even this foreshadowing too.
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(On the left.)
30. Because of this countdown.
31. Because the importance of a great joke was never underestimated.
32. Because of the symbolism of these clouds turning to blue skies.
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33. Because of how well the show made you feel for Ted.
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34. Because of how this saying came so very true. Twice.
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