Never end with a preposition

On my 65th birthday, I got a gift certificate from my wife.
The certificate paid for a visit to a shaman living on a nearby
reservation who was rumored to have a wonderful cure for erectile
dysfunction.

After being persuaded, I drove to the reservation, handed my ticket to
the shaman, and wondered what I was in for. The old man slowly,
methodically produced a potion, handed it to me, and with a grip on
my shoulder,
warned, 'This is powerful medicine and it must be respected. You take
only a teaspoonful and then say '1-2-3.' When you do that, you will be longer
and harder than you have ever been in your life and you can perform as
long as you want.'

I was encouraged. As he walked away, I turned and asked, 'How do I stop
the medicine from working?'

'Your partner must say '1-2-3-4,' the shaman responded. 'But when she
does, the medicine will l not work again until the next full moon. '

I was eager to see if it worked. I went home, showered, shaved, took a
spoonful of the medicine, and then invited Cara to join me in the
bedroom. When she came in, I took off my clothes and said,
'1-2-3!' Immediately, I was the manliest of men.

Cara was excited and began throwing off her
clothes. And then she asked, 'What was the 1-2-3 for?'

And that, boys and girls, is why we should never end our sentences with
a preposition.