If u use passwords that are complex like upper and lowercase, numbers, symbols it makes them hard to remember especially when u have many unique passwords.

Also, for work I have to change my password every few months which can't be the same/similair to my old password makes it difficult.

A password manager is the best way for me to solve this issue but I would understand if people wouldn't trust this since if ur phone falls into wrong hands someone has acess to all your passwords.