During the scene where the gang is making fun of Canada, a couple in the background meets, gets engaged, awaits the birth of their child, and celebrates the child's graduation. At the end of the scene, the woman, now old, mourns over the ashes of the man and then meets someone new.
Ted tells the gang he is taking piano lessons "again", so he can perform at the rehearsal dinner as a gift. He is seen playing piano with Victoria when they meet at Stuart and Claudia's wedding.
During the scene in which Ted Mosby is receiving his piano lesson in costume, the piece of music he is asked to play is the Black Key Etude by Chopin.
In this episode, Ted tells Robin and Barney that he is planning on taking piano lessons to perform for them as a wedding gift. However, in Season 1, Episode 13, he plays piano while Victoria tap dances.