...many men don't understand that we are in "don't get raped" mode pretty much all the time.
One day last week at the end of a day of work I was walking to my car. I was walking about 100 ft behind a female coworker, who was walking to her car. As I was approaching my car she turned around, and gave me a smile and said, "Ha, you scared me."
Jokingly I said, "I was actually thinking of pressing the panic button on my car remote as you walked by, I thought that would have given you a jump."
"Oh, a car alarm's not scary," she said. "A man following me though... you know?"
We laughed it off, exchanged pleasantries and got into our respective vehicles. As I started my car I thought, "No, no I don't really know."