Most internet users have serious troubles with passwords: they either choose to use the same password on all sites, use passwords that can be easily guessed by looking at the persons background or write all their passwords down to be able to look them up if they forget them. Only a few users use high quality passwords that they are able to remember.
One solution would be to use password safes that store all your passwords securely and can only be opened with a master password. Another method would be to use Password Grids, let me explain the concept. You use an 8×8, 10×10 or bigger grid and create one easy to remember pattern on it.