I was posting this on TIP because it came up in conversation, when I realized that I didn't remember whether or not I'd ever told it here. So, anyway, here it is, a completely true story of Kuus gullibility:
Once upon a time there was a Babykuus whose parents were super excited about celebrating Kuusmas with a kid. They bought tons of gifts and, being too excited to contain themselves the whole way to December 25th, they decided that if you could make a kid believe that Santa was real, you could make a kid believe pretty much anything, including that there was a special Kuusmas angel that thought Babykuus was soooo special and wonderful that she deserved to find a gift in her stocking every morning starting on the 15th (and various times throughout the day on the 24th) in addition to the usual Santa gifts. And they were right.
As the years went on, the gifts in the stocking were more and more like a gateway drug. In addition to gifts, Santa, the angel, and occasionally the tooth fairy wrote Kidkuus letters telling her how wonderful and loved she was, and how much they enjoyed getting her gifts that would be a tangible reminder every time she played with them that at this very moment, Santa (or the angel, or the tooth fairy) was thinking of her and smiling. Unfortunately, or fortunately, depending on how you see it, Kidkuus was pretty smart and had a tendency to question everything, and reject anything that didn't have a rational explanation as hokum. But knowing that Kidkuus was already a scifi fan, the Kuusparents had a plan in mind. With every question Kidkuus asked, a scifi style explanation was given, and of course accepted.
By the time Kidkuus was in her early teens, she had been pen pals for many years with those semicorporeal holiday beings who were able to come from their dimension through a rift in spacetime and leave her gifts and letters. Unfortunately they were unable to take any gifts from Kidkuus back with them, since three-dimensional objects only go through the rift one way (from there to our world; they had to ascend to pure energy to make it back through the rift themselves), but flat objects such as thank you notes and reply letters were close enough to two dimensions to make it back intact. And interestingly, all of the beings from that dimension had similar handwriting; it was a side effect of not always having physical hands.
So one year at 14 I was explaining this to a new friend (the friends I'd had since grade school were used to this story, I guess, and didn't want to burst my bubble), also a scifi fan, and his eyebrows about shot through the ceiling. Bless his heart, he didn't SAY anything about it being clearly bs - he just tentatively asked questions in that voice that indicates that the person asking is a little concerned that you might burst into flames of insanity at any moment. You know the one I mean. I was in the middle of answering his questions, when it hit me, all of a sudden. Midsentence and all, I was like "Oh, yeah, when they bring the gifts they can have physical bodies, but when they go back, they... oh hell. My parents made this up, didn't they?"
I went back to my parents and told them that the jig was up. They laughed and said they were glad I'd enjoyed it for as long as I had, and that they still kept all the letters I wrote. And now that I'm grown and married, Mr. Kuus and I carry on the tradition, leaving gifts and such for each other every day starting on the 15th from mysterious magical beings who love us.