I use LastPasss. It's now free for using on multiple devices. You can even setup a flash-drive live-linux browser with the plugin to run on someone else's computer.
Works great. Unique passwords for EVERY account. Definitely think of the "security questions" as "extra passwords". There is NO requirement that the question "your mother's maiden name" be TRUTHFULLY answered. Just make up some other password. I use LastPass to do that, and store the security questions and answers in the notes for the site.
You can always logout of LastPass and so then, you're down to memorizing the "last password" you need to remember. Make it a good one. Change it every couple of months or yearly. Make it a passphrase and not a password.
And then let LastPass do the work of remembering those impossible to remember random passwords. And because every site is a different password, anyone guessing one doesn't get any access to any other account.
And on your phone, you can simplify things by using their PIN function to set a 4-digit PIN that replaces the big long master password on your computer.
You can even use 2-factor to require a dongle/authy code to login and download your passwords safely encrypted on LastPass' servers. That way, when you logout, the ex can't login even if she knows your password. Stealing your phone and knowing your PIN is a different story. The LastPass folks are still working on that one. But it's light-years ahead of everything else and far, far better than any manual system you'll thunk up.
Lastly, you can export your entire vault into a text file and store it on a thumb drive to keep in your "in case of emergency" envelope with your lawyer or in your safe deposit box. Personally, I encrypt it using TrueCrypt/VeraCrypt with a *different* password and have instructions, start to finish, on how to plug in the thumb drive, mount the TrueCrypt drive using the emergency break glass password, and then access my passwords. I just have to mount the drive and export my LastPass vault periodically. I also have a text file with my one-time use emergency password codes for various accounts (including LastPass itself).
This comes in handy and you need your family/survivors to manage your affairs and TCB. There is no reason now that LastPass is free. The Premium version gets you some shared folders and I've not found that helpful unless you share accounts with relatives that have their own LastPass accounts. Even then, if you share a password, you share complete control over that account. It is helpful, however, if those accounts have 2-factor authentication on them (e.g. your EA/Origin or Steam accounts).
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