Why do farts smell bad?
>>28531821
why does blood taste like metal?
>farts smell bad
The sort of people that thought farts and related scents smelled good were probably less likely to avoid dying to disease, and so they were less likely to pass on genes, or influence society into sharing their opinion about those smells.
>>28531821
Methane
>>28531828
Iron
>>28532360
Also sulfur. I forgot.