A childhood belief about i'm different

When I was about six years old my sister (who was 11) and I had to do the dishes together.
My sister used to get mad because she always ended up doing more work than me...
So one night she came to me with a "Family Secret". She said "Do you know why mom never
makes you clean up as much as me?" "No, why" I said. "Oh never mind I can't tell you, becuase
you'll tell mom that I told you and I'll get in big trouble!" she continued. "No I won't, I promise!" I whined.
"O.k., she said "But you have to PROMISE not to tell!!"she coaxed "I won't I promise"I replied.
She took me out onto the back porch where we could be sure no one would hear, and she said "You were
adopted, you're really 25 years old, your just a midget. Mom feels bad for you and that's why I
have to do all the chores."
I was mortified! Being 6 years old none of the obvious questions came to mind...
Like why don't i remember the first 20 years of my life!! :D I kept my composure for what seemed to be
an eternity but by the end of the night I was crying to my mother asking her why she never told
me I was really 25. After my mother finished laughing she was Irate to say the least!