An old chestnut came up recently: the relationship between "containment" and "cascade delete".  Somebody said that this is something inherent in real things and trotted out an old example: a Car has Wheels and when the Car is deleted, so are the Wheels.

The UML specification is full of this kind of nonsense.  The verb "delete" does not apply to cars, boats, wheels, or propellers. You can't delete a car any more than you can conjugate it or grow it. The only thing that "delete" might act on is a software entity that models a car.  Such statements do not represent the semantics of real things; they represent modelling choices.  Only computer scientists are capable of thinking otherwise.