It's wrong to memorize your recovery words, anything can happen to you and you won't remember the words anymore, it's a lot safer to have a hardware wallet or keep your recovery phrase written in a safe location.
Theres a popular belief that the human brain can store more information and data than the computer can do, but in this case, I disagree with that. It is better you write it down and save elsewhere or in an hardware wallet rather than trying to memorize it. The seed phrase is very sophisticated and hence, they cant be easily assimilated into the brain to stay for a long time, not when we have so many things going up in our brains all the time.
What I did was simply encrypt it in a secure box and save it on a laptop that I no longer use and as a backup I saved it in a secure file on Box.com. I think that this is quite safe, considering that it is encrypted, and I also put some of my assets on the exchange, so that even if I lose access to my wallet I still have backup funds on the exchange.
While putting some in that exchange, hope you put only the one which you can afford to lose. Im sure you did that because no person will save more money in exchange than a decentralised wallet where they have complete ownership of the funds. Only a novice that have no knowledge of crypto will do that or the ones that are negligence in events like this.