Try to answer next simple questions:
- What is length of your passwords?
- Do you use mixed letters, digits, and special characters?
- Do you mix uppercase and lowercase letters?
- How often do you change you password?
- Can your password be found in dictionary?
If you follow all guidelines about so called strong passwords, it is question how to memorize them. You will probably need password safe (here). However, there are tools that can recover passwords when you lose them, but they can be used to “recover” passwords that belong to another person.