How many different cars can you drive?
There are two essential interfaces to the overwhelmingly complicated internals of modern cars:
Without a common interface, you would need to learn how to drive each new model/vendor of car -- a nightmare!
What we see: through a generic interface we can interact with a huge variety of different types/brands/models of an “object” in the same way (wouldn’t it be great if this were the case with VCR’s?)