Yes... I'll definitely memorize them. Benefits? Well, that's just about you being on the safer side. The big setback is life itself; if anything happens and you lay down lifeless, that's the end!
Well you could leave a few last words and tell someone you’d actually like and respect to trust with your secret. It could be in a form of will and testament. Or just hand them a paper indicating where the back up copy is.
You've got kids? Teach the eldest amongst them and, show 'em.
Please make sure that your kid is not a child. If your kid is still a child, they might not understand just how severely serious this is and might tell everyone or anyone about your seed phrase.