Private keys and seed phrases matters because they prove you're the true owner of your crypto wallet and funds. Without them you can't access your wallet. It's your responsibility to keep them safe, because you have the full control over them. If you lose your private key and seed phrase and someone else gets access to them, it can lead to permanent loss of your funds. Both should be stored privately, and you shouldn't reveal this information to parents, friends, or anyone else for the safety of your assets, because they might unintentionally or intentionally expose or misuse your security, which may put your assets at risk. To protect your assets, it's crucial to keep this information confidential and secure them at all times.