Pet peeve that I can't comprehend how it happens: sinks with faucets that barely extend out over the bowl, resulting in you knocking your hands against the edges of the bowl while trying to get them u...
Also, “water saving” faucets and showers that dribble out water slowly, so you have to sit there rinsing for 5x as long, which balances out the total water used, and leaves you poorly rinsed.