We humans struggle with this work and often succumb by abandoning the basic hygiene of using a different password at every site. Password reuse turns a data breach at one site into an opportunity for attackers to try your exposed password at others.
“I don’t know anyone who thinks they can keep complex and different passwords memorized,” emailed Lorrie Cranor, director of the CyLab Security and Privacy Institute at Carnegie Mellon University. “If you adopt a password manager, you don’t have to think about coming up with unique and strong passwords anymore and you don’t have to figure out how you are going to remember them.”