Yes, the best possible solution to that (which comes to almost everyone's minds ) is "Let's write it somewhere". But is it safe??. I don't want to expose any of my passwords by just writing them on a piece of paper.
The next immediate option is to keep it on Mobile. But generally, it's difficult to organize passwords on mobile notepads or text files.
*PassKeeper solves the exact same issue*. Providing a card interface to same and manage Different Accounts and their credentials.
In short, the focus of the application is to:
If you haven't tried the App yet, download it from Playstore