Any password you can remember is a password that is already in thousands of crackers' try-these-first password lists. All of the online security breaches of password database have provided a rich and extensive database of passwords that people actually use. No, you need to use a password manager. Like five years ago. But a password-managing device is the worst possible option you can consider. How can you back up your password database?
A good, completely off-line option is Steve Gibson's 'Off the Grid' password generator here: https://www.grc.com/offthegrid.... You could generate a paper grid and use that. It can be reprinted as needed, and even if you lose it, no problem.
Some/all of the cloud-based managers can be used offline. I know for a fact that LastPass does not need to be connected to the 'Net to work. It's free, try it out - see if it works for you. There are 'LastPass Portable' versions, designed to run off a thumbdrive.
For a buck a month, LastPass provides stellar technical support (one of the programmers called me at home to sort out an issue I was having when using 'LastPass for Applications' with the steaming pile of a crap that is iTunes): https://lastpass.com/go-premiu... Their security has been vetted by trusted reviewers, they use best practice encryption and protocols. Perhaps their Enterprise services will fit the bill?
Cheap at twice the price. I can't recommend them enough.