No, I own two. One for regular wear, the other is for when I ride my bike or run outside. I think two is a perfect amount, especially if you lose or break one.
One pair is certainly not enough! Everyone knows if you only have one of something, you’ll never be able to find it, but if you have two, you’ll always be able to find the one you weren’t looking for. That’s why I have two.
I have a huge number of pairs of sunglasses because I act and sometimes a character calls for a certain type of glasses. Ordinarily I don’t wear sunglasses at all. That’s what tinted glass is for.
I have a pair in my mother’s car, a pair in my father’s car, three pairs in my own car (in case a passenger needs one and doesn’t have their own) and a pair that I carry in a case in the bag I keep with me.