A flat-chested lady goes to a doctor to get a recipe for bigger breasts.
He tells her "alright, I do have a recipe, but you have to do precicely what I say. You have to rub this cream on your breasts every day at 12:00, 16:00 and 21:00 while singing 'scoobie doobie doobies, I want bigger boobies'. "
The lady, who at this point is absolutely desperate, is quite willing to try this apparently ridiculous recipe. So every day, three times a day, she rubs the cream on her chest while singing "scoobie doobie doobies, I want bigger boobies". Several weeks later, her breasts are significantly larger.
One day, while she is on the bus, she realises with horror that the time is almost four, and the bus is caught in a traffic jam. She shallows hard with her eyes on the clock while thinking what she can possibly do. Ten minutes to four, five minutes to four... At precicely four o'clock, the lady strips from the waist up, applies cream on her chest, and starts singing "scoobie doobie doobies, I want bigger boobies".
Her audience is flabbergasted. "My dear madam! What are you doing? You're gonna be arrested for public indecency!"
The lady, undeterred, "Scoobie doobie doobies, I want bigger boobies."
"Ma'am! Stop at once, or else I will call the driver!"
"Scoobie doobie doobies, I want bigger boobies."
After realising that talk was futile, the passengers do call the driver. He comes at once.
"Ma'am, please put on your clothes."
"I can't put on my clothes. It's four o'clock."
He drops his pants immdiately and starts:
"Hickory dickory dock..."
The dumber people think you are, the more surprised they're going to be when you kill them.