Physical wallets are prone to being lost, wiped, damaged.
I prefer to just memorize the private key.
You seem to be a smart guy if you can memorize your private keys. I stick with a trezor for my big wallets and online solutions like blockchain for coins i want to spend.
Coinbase is also quite good btw.
No way this guy remembers his private keys, he must be insane with combinations (or have a photographic memory) if he is able to remember them with 100% accuracy.
I have coinbase as a payment wallet, and I use a paper wallet (With admittedly not very much on it) for a storage and safe wallet.