I personally think that one of the best and easiest ways to store valuable information is by doing the following:
Open a gmail account: www.gmail.com
Then choose an easy to remember password / passphrase with complexity e.g. I.L0v3.Sw1mm1ng@12345 (Use a different number).
Go to your account section and enable 2 Step Verification: https://myaccount.google.com/u/1/security
Access Google Drive: https://drive.google.com/drive/u/0/my-drive and upload a text file with your password to it. Once done, delete the text file from your computer.
This way, even if your computer crashes or gets stolen or if your house burns down or is robbed, you get access to your passwords from almost anywhere.
If you'd like to add an extra cool feature, you could use Steganography and encryption. I've bought some $BAY: bitbay.market They have incredible software that allows you to hide files in images and more. You could do this and then upload the image to your Drive.
Peace