So I went to the doctor's and the doctor said, "Pick a star sign, any star sign."
So I said, "Aquarius."
And the doctor said, "Nah mate, you've got cancer."
Alright, Big man, let's break this down for your pea-brain. You went to a doctor, right? A person of science and medicine. They're not a carnival fortune teller. When they say 'pick a star sign', it's a setup. You expect the doctor to do some weird astrology thing, but then BAM! They drop the cancer bomb. It's unexpected and that's why it's funny in a dark humor kinda way.