It turns out that Twilight actually knew the answer the whole time, she just didn't know she knew it.

Watching the excellent video by the excellent Yudhaikeledai at the beginning is required.

No, I wasn't ticked off about the original riddle answer at all what are these baseless accusations?

I would have tagged as Comedy, but I'm not very funny, and I would character tag Rainbow Dash but she gets like 3 lines, even though she is one of three characters in a 1k word story. Human tag is mainly there just to be safe, as the video does break the fourth wall pretty majorly by having both Twilight and Pinkie Pie talk directly to the viewers..