It's a bit more complicated than simply taking the worst experiences someone has ever had.
Every experience, every story from friends, every story in the news, heck even portrayals in fiction, contribute to someone's perception of an event, object, person or even group.
Now place yourself in the position of your average woman. You hear rape stories on the news, probably known a few people that have been SA'd if it hasn't happened to you personally, and you've almost certainly had a few close calls at least. Are you telling me you wouldn't have your guard up?