The Giant Cockroach

One thing leads to  another. One snail joke reminds me of another. A snail coming to the door reminds me of something else coming to another door. And so it goes...

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A man hears a knock at his door one day. He opens it to find a giant cockroach, who slaps him and runs away.

The following day, he hears the same knock. He opens the door to find the same roach, who again slaps him and runs away.

For the third day in a row, he hears a knock at his door. When he opens the door, he sees the same roach, only this time, the roach punches him in the face, breaking his jaw.

When he goes to the hospital for treatment, the doctor asks him how it happened. He then relates the whole story of the knocks on the door, the cockroach, and the slaps, ending with the punch.

The doctor nods wisely, and says, "I see. Well, there is a nasty bug going around."