A life-lesson I learnt when I lost my notebook and passport whilst travelling several years ago, was to ensure I have access to all my important information like all passwords, passport numbers, important phone numbers, etc even if I lose my technology. For me this means keeping an encrypted file of my passwords on Dropbox. The file can be decrypted with OpenPGP that can be downloaded from the internet. Important phone numbers should be printed on a card somewhere, maybe with the phone numbers obfuscated so that if someone steals it, the phone number isn’t easily identifiable.
The alternative to keeping an encrypted file with your passwords, is to use an algorithm to generate them. If you base your encryption key on the website name, and then have your own algorithm for generating a password from the key (in a non-obvious way), then it is easy to recover each password just by following the algorithm.