A - aren't using one of these, and if you are, to change it.
B - see how easy it can be to get into someone's account/computer (because not many people use strong passwords).
C - learn about tools to help you generate passwords that are very hard to crack.
20 Most Common Passwords (source: Imperva's Consumer Password Worst Practices report on passwords disclosed in RockYou Media breach, via informationweek)
Now for 3 tools/links to use that helps you generate strong passwords