Ability to keep a secret
At minimum, Monica Lewinsky spilled all the details to her coworker Linda Tripp. Mimi, however, guarded her secret closely and carefully until she and her husband divorced in the 90's and she told a handful of her best friends. Her secret came out when detailed oral histories of JFK mentioned her, and the media tracked her down in 2003. She released her tell-all book this year, roughly 50 years after her affair.
-
[photos via, via]