It's passed down from person to person, "don't buy a lens that has fungus". But why not? What does it actually mean? Can it be removed easily? If it can, does it harm the lens? I may be showing my ignorance here. But I've only seen people say not to buy a lens with fungus, I haven't seen anyone say why. I assume it is just more hassle than it is worth to buy a lens with fungus on the cheap and clean it.