This closely parallels the situation with the immune system.
One might think “I want a strong immune system. I want to be able to fight every dangerous pathogen I might encounter.”
You go to your local friendly genie and ask for a strong immune system.
The genie fulfills your wish. No more seasonal flu. You don’t need to bother with vaccines. You even considered stopping to wash your hands but then you realized that other people are still not immune to whatever bugs might there be on your skin.
Then, a few weeks in, you get an anaphylactic shot when eating your favorite peanut butter sandwich. An ambulance takes you to the hospital where they also tell you that you got Hashimoto.
You go to your genie to ask “WTF?” and the genie replies “You asked for a strong immune system, not a smart one. It was not my task to ensure that it knows that peanut protein is not the protein of some obscure worm even though they might look alike, or that the thyroid is a part of your own body.”.
This closely parallels the situation with the immune system.
One might think “I want a strong immune system. I want to be able to fight every dangerous pathogen I might encounter.”