Lies at school
As a child while honest enough, I had a negligible grasp on the truth. Life was so boring I felt the need to make things up, and once I'd said it/written it down part of me honestly believed it had happened.

Two incidents that spring to mind that led to embarassment for both me and my family are the following

(1) I had a lovely new dress and was very happy with it. My mother had invited a priest round to do a blessing on our new house, and he made some polite comment about the dress. I promptly informed him that it was the dress I had worn to my mummy's wedding. Since my parents had been married for ten years before my birth, I'd performed quite a feat of timetravelling.

(2) The other one got me into a lot of trouble. People may remember that in reception/first year you sometimes had to write about what you did at the weekend. I wrote that I had stolen my mother's diamond engagement ring, sneaked out of the house at night with my neighbour (a boy about the same age) and we'd had a big adventure, then buried the ring under a tree. The teacher told my mother about it, and I got a massive bollocking, and when they found out everything bar the sneaking out (alone as it happened) was a lie, I got told off even more for lying
( Amberl was stripey and dominated Europe, Thu 12 Aug 2010, 15:21, 2 replies)

As a child i had a very loose grip on reality
I can really really identify with this, except the priest and the dress thing... i am a geezer after all
(TwinkleFuckingToes Has a ingrown toe nail, Thu 12 Aug 2010, 15:28, closed)

News Book
I recently found mine and my sister's 'News Books' from early primary school and nursery and they are full of complete fallacy - notably, my sister claimed to have been 'A duck in a play'. A bit less imaginative than your claim, but a touch more bizarre - I mean, why?!
(Sinister Carp doesn't mind the gap, Fri 13 Aug 2010, 12:01, closed)