The Internet has become a massive data aggregation tool, providing entire lifestyle and consumer profiles about people to a host of anonymous entities. If you participate in social media tools like Facebook, your life's details are not only being harvested by marketing firms but by hackers as well.
Many social media sites offer up seemingly harmless quizzes and games that serve up questions urging you to reminisce about specific areas of your past, like "What was your first job?" You can substitute the word "job" with a host of other words—like pet, car, school name, etc.
Other questions might be, "What was your favorite teacher's name?" Again, you can substitute a number of words for teacher—like movie, book, school mascot, etc.
These questions are no different from the secret questions that you use online to reset a lost password or unlock an account. By sharing the answers with anonymous sources you are giving away the keys to unlocking your online accounts.
Although most people won't give away this kind of information, you'd be surprised at how many do. Whether you think you trust the source or not, always avoid answering questions like these in chain emails and social media "quizzes" and surveys.
Also, when configuring your secret questions and answers for unlocking online accounts, be sure to use information that is not readily available through your online persona.
For more information, see Brian Krebs' posting entitled Don't give away historic details about yourself at https://krebsonsecurity.com/2018/04/dont-give-away-historic-details-about-yourself/.