Special cases such as Torricelli trumpet are often used to construct the existence of special cases.
For example, regarding the differentiability of continuous functions in mathematics, it is hard to imagine that a function is continuous but differentiable everywhere.
For a long time, mathematicians thought it was impossible until weierstrass constructed this function by using infinite series.
Make the understanding of continuity and differentiability in mathematics more profound and rigorous.
Similarly, the Torricelli trumpet is a similar example, which is more a model for the rigor of mathematical theory.
The above are personal opinions and are for reference only.