I've always thought that this was the difference between vegetables that I grew up eating in Italy and the ones I eat here in the States.
The most obvious difference for me have always been zucchini. In Italy they are small and scrawny, with prominent ridges, making them fairly star-shaped in cross-section. In the US, though, they are large and swollen, the flesh between the ridges expanded such that they are usually completely circular in cross-section.
I have never really been surprised that my zucchini pasta doesn't come out nearly as well here in the states.
If only my bucket-garden on the roof produced more than one tiny zucchini, perhaps I could use scrawny homegrown zukes.