Small thing-big difference

I just finished marking our first big unit test for Literature and I noticed that almost every student got 100% on a particular section. They all clearly remembered the elements of a Romance poem and were able to apply them to the poem "Sir Gawain and the Green Knight" that we study in Lit. All I did was this:

1. I put the notes for "Elements of a Medieval Romance" on the overhead.
2. I gave the students different coloured sheets of photocopy paper (they got to choose the colour-small choice but they liked it) Oh and I gave them smelly felts-they LOVE smelly felts!
3. Then I had them write down one key word from each of the notes (they had to pick the most important word). I told them not to copy down anything else because I would give them the full notes afterwards.
4. Once the kids had the words written down they had to take a piece of tape and make their sheet of paper into a wizard's hat.
5. I told them we were making the hats because the story of "Harry Potter" includes all the elements of a Medieval Romance. We went through each of the points and confirmed they were all found in "Harry Potter" books and films.
6. Kids then had to stand up and recite two elements of a Medieval Romance to a partner from memory (or by looking at the other person's hat).

So why did they remember it?

Because they had to think of a key word to condense the info?
Because they had a visual memory aid?
Because it was hands on?
Because they had to stand up and verbally express some of what they remembered?
Because it was connected to Harry Potter which is relevant to them?

All I know is that they nailed it on the test a week later.