Before Louis Pasteur's disproving of spontaneous generation, most people believed that bacteria and putrefactive organisms like maggots etc. spontaneously poofed into existence, like a video game character spawning. Pasteur suggested that maggots came from flies laying their eggs on rotting meat etc, and that bacteria were everywhere and will multiply quickly under the right conditions. A lot of people at the time thought these were crackpot ideas.

Imagine this guy trying to explain this discovery to people who spend days reading and responding to articles trying to calculate how many angles can fit on the head of a pin.

And if you believe that, then you'll believe anything... that is supported by hard evidence and deducted from those by sound logical principles.

Wierd part is you can actually see it with a microscope. Anime Parallel world pharmacy made more sense then real life.