A childhood belief about rude bits

I used to believe that 'Shagging' meant flopping around, after reading a book about a shaggy dog with floppy hair.
I was about 7 years old and i was watching a tv show called 'top of the pops' with my sister and the babysitter who was looking after us.
The man who was singing on it was wearing tight leather trousers and was dancing in a way that made his willy 'flop around'.
So i exclaimed "hey look his willy's shagging!"
my sister who is much older than me burst into fits of laughter along with the babysitter.
I sat there laughing with them because i thought they found it funny that his willy was 'flopping around' too.
later on that evening they told me what 'shagging' really meant.
:D
oops!