It is October, so three Halloween-themed jokes are made here. All three revolve around a wacky misinterpretation of the tradition of pumpkin carving.
1. He carved a pumpkin into a pumpkin, a meta joke.
2. Nitro glycerin is used both as an explosive, and a treatment for heart conditions such as angina.
3. The woman is projecting her own insecurities about adulthood onto the pumpkin. It is assumed that this character represents the Author.
4. A reference to the Banach–Tarski paradox - a paradox that states a 3d ball can be split into pieces and reconstructed into two identical copies of the first ball. It is built upon The Axiom of Choice is an often-debated axiom dealing with infinite sets and recursion. Except in this case the ball is a pumpkin.
