Memorizing one's wallet seed phrase is never the best way to storing it, as you never can tell, you may forget it when faced with stress and life challenges. Hence, the best way remains writing it on multiple pieces of paper just like you said you did, and storing it in multiple different locations in your house without writing certain keywords such as "My wallet Seed phrase" or either "My Electrum Seed phrase" or "Trust Wallet Seed Phrase", so as to make it hard for anybody to understand what it means if they happens to come across it, as these are the most common keyboards people always use as title of the piece of paper when writing a wallet seed phrase.