I have several hundred online accounts. There is no way I could possibly remember the passwords or even the usernames for all of them. I used to just use the same password for most but then sites started adding conflicting password complexity rules and change policies. Now I use LastPass for the non financial accounts and have to remember the complex password for the rest. Although technically the passwords are not as complex for the ones I need to secure but LP has been hacked multiple times so I don't trust its usage for financial accounts.