Okay, here's my story. It can be shocking!
I was born 19 years ago in the horrible town Enschede in The Netherlands. When I came out of the womb, the doctors were in complete shock. That was because there was a round hole in the place where my genitals should be. Inside the hole, the doctor could see a screw-pattern. So it was obvious that something had to be screwed in.
Then my mother gave a loud scream and the doctor rushed towards her. There he saw that my mother gave birth to two more things: a penis and a vagina, both with a screw in the end. The doctor realized that my parents could choose my gender, and so they chose the penis. My mother decided to take the vagina home as a reminder of this bizzare miracle. My parents never told me about this happening.
Then, years later, I found the vagina while cleaning up the house. I was very curious why it had a screw and wondered if my penis had that too. So I tried to unscrew it and it worked.
Since that time I'm a he from monday till friday, and in the weekends I'm a she.
I hope that it's all clear now. But don't hesitate to ask if you have a question.
I have been on holiday to Greece for 2 weeks and now I'm back and the first thing I read here is "The Rikkertje Mystery"!!! 
, I always knew it 
