Simple solution:
- do not encrypt wallet.
- write down your password on a piece of paper and hide it somewhere safe. (uh another problem, he cannot remember where did he kept the paper)
- have password hints
- use all the letters in the alphabet as password or use your name in reverse as a password.
It is not a secure solution ,you must always encrypt your wallet but you can always save your password and pass phrase in a note pad which is not that difficult and keep in a safe location,never use password hints and easy ones since you are dealing with money and make sure you put in a very good password so that no one is able to crack it easily.
I agree, you should make counter measures for yourself to avoid getting locked or losing bitcoins. if you are forgetful and you can't remember the password/passphrase, just make a back up file of your password/ passphrase and store it in flash drives, external hard disks or in google drive (just make sure that your account is protected) and, don't use same password you used in your wallet and lastly, make a back up your wallet.dat just in case of data corruption.