Lost Backpack

Jackie misplaced his backpack at camp last Thursday. He was upset and told one of the camp counselors "Oh, no! Now I'm not going to be able to go to school anymore!"

I've checked lost and found, but it hasn't turned up. Jack was wondering today where it disappeared to and I thought I'd ask his opinion about what he thought happened to it.

"Well, I had it in the locker room and then I had to go to the bathroom and while I was in the bathroom, I heard my backpack say the magic words and disappear."

What are the magic words?

"Feliz Cumpleaños."

Happy birthday, little backpack. Guess you turned one and ran away.