Embarrassing childhood memory

So when I was about 7years old Radio Hauraki (local rock station) had a competition to ring up with a joke. Whoever told the best joke would win their mother a jewellery box for Mother's Day. I had a joke I thought was pretty darn amazing and really wanted to win this jewellery box for mum.
So I phoned up and I got through, my first ever phone call to the radio & I was so excited, they asked my joke & I was so scared, embarrassed and excited all at the same time that I ended up telling the joke the complete wrong way - I was mortified. Instead of the following correct joke was (bearing in mind I was 7 and this was pretty funny)

Knock Knock
Who's there
Grandma
Grandma Who?
Knock Knock
Who's there
Grandma
Grandma Who?
Knock Knock
Who's there
Grandma
Grandma Who?
Knock Knock
Who's there
Aunt
Aunt who?
Aunt you glad that Grandma's gone?

Poor little 7year old me told it as Aunt the whole way trough, meaning that the punch line made no sense. But those awesome Radio Hauraki guys ended up gifting me the Jewellery Box. I received a letter and everything as I ended up in tears on the phone. Can't remember how they got my details I think it was all part and parcel of getting through to tell your joke.
Only other part of this story was my mum had no car and we couldn't get into the radio station to pick it up. So even though I ended up winning we never saw the
Prize.