@Derpy You'll wait a full two weeks before watching the next episode again, aren't you? Well, I can't blame you this time. Maybe you do need to arrange to watch that at exactly the right time. While E19 was just a fun gag of the week episode that you can just forget if the inconsistencies don't add to the universe, E20 is serious business and need the time to think the implications through and settle them down.

In S6 E8 A Hearth's Warming Tail, since everyone is already celebrating in the castle, how come Pinkie doesn't come up and act and sing the part of the Spirit of Hearth's Warming Present in the tale? Why does Twilight get to do it all by herself? I don't understand why Pinkie misses such an opportunity to sing a song.

I also still don't understand Pinkie in S6 E21, when she was more upset about some burnt cakes than how Starlight told her there was no time to sing. You can always just make more cakes, but having an episode without a good song is not so easy to fix.