People who buy something cheap that you know will break in no time, instead of paying for a better quality item, and paying more in the long run.
My s/o insisted on buying a far less expensive hand held shower head. Just couldn't see the point of dropping a few hundred dollars on something she could get for 79.99 at bed, bath, and beyond. After arguing that her shower head would be broken within 2 years, and getting no where with that, I let her dig her own grave.
I was wrong, it lasted 8 months.