Donna Talarico sat at her computer one morning, stared at the screen and realized she had forgotten—again!—her password.

She was having financial difficulties at the time, and was reading self-help books to boost her mood and self-confidence. The books talked about the power of positive affirmation—which gave her an idea: She changed her various passwords to private messages to herself, like "imawe$some1" or "dogoodworktoday."

"It's...