Paper can be really fragile, and all it takes is a tear or water spill or defacing to deny you access to your BTC forever.
You are inventing the wheel all over again 
We all know that paper is easy to get damaged, burned or destroyed by water, but that can happen to all your paper copies.
It's much better to use secondary backup option something more substantial, made from stainless steel, it can be washers or metal plates, whatever you prefer.
So, you should make a second copy of your seed phrase that is identical to the first, and store it on a different place from the first seed so that they both cannot go down together except in extreme circumstances like a natural disaster.
I wouldn't stop at only two copies, because three is better than two.Adding one or more passphrase is also a good suggestions, and multisig setup is even better.
it is kinda worrying leaving your seeds somewhere someone can find but for sure there are solutions. This is the real risk of crypto currencies.
Your brain is much worse place to keep anything important, especially something like seed words.This is the real risk of human body experience, and you wouldn't be the first to lose coins for trusting your brain so much.