A 9-year old neighbor friend of mine, knowing that I liked teddy bears, told me this joke:

Once upon a time, in a town populated by teddy bears, there lived a baby teddy bear and his Mother.

One day, the Mother teddy bear asked her son to go down to the corner store to buy her a pink bar of soap.  The baby teddy bear jumped at the opportunity, since it was a big responsibility and he was always helpful around the house.  So the baby teddy bear hopped on his bicycle, and rode down to the corner store, all the time saying to himself "pink bar of soap, pink bar of soap"' so he wouldn't forget.

Finally he reached the corner store, parked his bike in the rack provided and walked inside.  He said to the teddy bear storekeeper standing behind the counter: "I would like to buy a pink bar of soap for my Mother." 

"Just one moment son, and I'll check to see if we have any in stock," the storekeeper teddy bear said; and he went to the store room to check.  A few moments went by and the storekeeper teddy bear returned, carrying a bar of soap.  "I'm sorry, son, but it seems that we ran out of pink bars of soap.  But I do have purple."

"That's okay, sir," replied the baby teddy bear.  "I'm riding my bike."

****** Pause ******

After a few minutes of trying to figure this out and assuming my friend was holding the punchline for effect, I said "I don't get it!"  To which she replied, "Oh, you're not supposed to get it, it's a TEDDY BEAR joke!"

****** I still don't get it -  ******