Faeries in my garden, monsters in my bath

Santa Claus was real. Or so I stubbornly believed until I was seven. The jeers, teases and insistences of my peers didn't convince me: Santa Claus existed, and I had seen him. Even my parents telling me that they were "Santa Claus" and put the gifts under the Christmas tree couldn't change my mind: I was certain of what I'd seen. One Christmas night, I had woken up to a bright light downstairs, stumbled down the stairs and saw Santa - every bit as round and jolly as the stories said - lining my presents under the Christmas tree, eating the chocolate cookies I'd left for him in a plate, and then disappearing (we didn't have a chimney).
So my belief remained until my seventh Christmas, when, intent on proving to everybody that I had been right all along, I stayed awake until I saw light downstairs and then sneaked down with a camera. My grand plan was to take photos of Santa: who could deny his existance if I had photographic proof? (The fact that I couldn't really take a photo with a toy camera didn't cross my mind… it was shaped like a camera, it clicked like my dad's camera, so it had to be a real camera, I reasoned.)
To my great dismay, however, I found my parents, both in their pajamas, eating the chocolate cookies. Imagine the scene… Christmas presents under the tree, two adults with a half-eaten chocolate cookie in hand, and a desperately crying child.

A house for "my" gnomes

I didn't only believe in Santa, though. I believed in gnomes, and in faeries.
I made a house for the gnomes once, and put it in a corner of my garden.
According to my books on gnomes, they would come out and talk if you were nice to them, so I tried my best: the house had a pool (a small bowl full of water, which I changed twice a week), a living room (with a sofa stolen from my Barbie's house), and even a bathroom (with an eggcup for a toilet: it was "just the right size", I insisted, much to the amusement of my parents). I even sewed some little red cone hats for the gnomes, and was very dismayed when, after a week, no gnomes had come say hello to me.
It must be because of the tree faerie, I decided. After all, if I stared at the tree leaves just right on a windy day, I could see her face, and she was much, much larger than the gnomes: so it was logical that they were scared of her, and would not come to my garden. So I turned to doing nice things for the faerie.
I watered the tree every day, religiously treasured the small leaf that happened to fall from the tree while I was there (it was spring, not autumn, and leaves didn't fall often), and once even tied my favorite hair ribbon to a branch of the tree. I believed the faerie was so pretty that she deserved a hair ribbon much more than I did.

The monsters in my wardrobe

I also believed, as all kids did, that there were monsters in my wardrobe. I absolutely could not sleep unless the wardrobe was perfectly closed. Fortunately, no monsters lurked under my bed; they did, however, hide behind my room's door, so it always had to be opened fully (it opened inwards towards my room) by my mom, so the monsters would be squished between the door and the wall and disappear for the night. There was even a "bath monster", a very flat white monster which lied in wait in the bottom of the bathtub. That monster was the reason my parents had to run a bath for me and I could not do it on my own: they were big enough to scare the monster away.
Monsters also lurked in an old building in a road close to my house. You could hear a strange noise coming from inside if you listened closely at the door; it was the monsters, running around in circles and shouting about all the evil things they were planning to do. They were responsible for all sorts of bad things: from snails eating my mom's rosemary, to the poor worms left stranded on the driveway after rainstorms, to all my kittens disappearing one by one. (I later discovered that my kittens didn't disappear - they ran away, because the stray cats that "owned" the area didn't want competition. But I still believed the evil stray cats were sent by the monsters, until I was almost ten years old.)

"He" dog loves "she" cat

Speaking of kittens, I don't know where I got this idea from, but I thought cats were all females and dogs were all male. Dogs chased cats because they wanted to make kittens and puppies, not because they were enemies. I had this very cute mental image of mommy cat taking care of a litter of puppies and kittens, and daddy dog circling the area looking menacing and making sure nobody tried to harm them.
I also remember asking my parents if all animals chased each other around when it was time to have children. Of course, that prompted the usual stories about how babies are "brought" to the parents, or are "found" by them. Unfortunately my mom and my dad separately told me both versions, one each: mom told me that babies are brought to the mom by a stork, and dad told me that babies are found by parents under a cabbage. This sparked the odd belief that storks bring babies to cabbage fields, and leave each baby under a cabbage, then the couples which want a baby head to the cabbage field, pick a random cabbage and find their baby under it. This lasted until I was thirteen, and it came time for the infamous "flowers and bees" talk.

The queen behind the mirror

When I was nine or so, I saw a very fascinating movie... "Return to Oz", I think it was called. It featured Dorothy (from "The Wizard of Oz") returning to Oz, and saving the world from an evil sorceress which had a lot of spare heads by freeing Ozma, the rightful queen of Oz, from the mirror she had been imprisoned in. The movie had such an effect on me that for a while I believed my reflection was indeed not me, but a girl from another world which had been trapped behind the mirror. I spent a lot of time trying to grasp the hand of the girl in the mirror with my own, so I could pull her out and we could be friends. When that didn't work, I resolved she liked being behind the mirror and being my reflection, and had forgotten she was supposed to live outside of it, so I started doing really quick and sudden motions in front of mirrors. I thought that if I moved really really fast, I could make the girl in the mirror mess up and realize she was not supposed to be my reflection. Then she would let me pull her out.

That's a secret

After that, I believed for a short while that objects could breathe. I would open all the drawers and cupboards in the house whenever I could, so the things in there could breathe properly, and then close them again before my mom noticed. This lasted for a few months, until I was caught in the act and informed by my mom that objects could indead not breathe, and therefore there was no need to keep the drawers and cupboards open. Despite that, the drawer in my room where my My Little Ponies and my Barbies were stayed open whenever I was in the room.
It all sounds so silly now that I've written it down - but I really believed those things, and though I now laugh looking back on them, they were the world of my childhood.
Besides, I still believe in magic - but, shhh! That's a secret!