(1) real mozzarella has a very short shelf life: 2/3 days for the real thing, up to two weeks for the best commercial products.
therefore (2) when you go out there and order a pizza, it will be made with an industrial produced copy of the real mozzarella because (3) real mozzarella is too expensive.(4) real fresh mozzarella is too good: just eat it on its own, at room temperature, and feel the stabs of pleasure up from the palate and down to the spine.
(5) oh,by the way, that stuff you find on supermarket shelves is only good to kick against a wall. several times.
on my pizzas i use cheddar.