So many weird old religious rules started out as trying to keep unenlightened but highly religious groups alive, fed, and disease-free, and somehow we've hung onto so much of it. For another example, check out the origin of sacred cows.
Madness string 93202
Eh, you're probably actually the figment of someone else's dream. When they wake up, you'll just go poof. If you now feel existential dread, congratulations! You're probably awake. (But you could still be the dream of a dread god.)