Yes, two. One was my first best friend in college. My excitement at being away from home and on my own for the first time was all wrapped up in my joy in having a wonderful new best friend, and so I was very slow to see what was becoming obvious to everyone around me. She told long, elaborate stories that I completely believed. I was the only one who was surprised when she got pregnant and dropped out in the second semester. She taught me to be a whole lot less trusting and gullible, and she showed me how easily I was seduced by genuine charm, which I mistook for character. I was 17.
The second was a babysitter who came to our home several times a week, bringing her young daughter, to look after my two preschool-age sons. I noticed little things not adding up but didn’t really put it together until she accidentally tape-recorded herself on our message machine taking a very long phone call that revealed the truth about a lot of things, from made-up stories about my husband to the fact that she was having an affair with her husband’s father. I listened to only enough to be sure what I was hearing. Then I fired her fast but worried for months that she would come back and do something to my kids. Scary. To this day I sometimes worry about her daughter.
If there have been others, they have fooled me, and so I guess I don’t really know how many.