When your best friend is on the other side of the country and 90% of your friendship has been spent on IM, 5% on the phone or Skype, and 5% in person.
When your greatest relationship is with a guy you've never met, and you prefer it that way, and he understands you better than anyone you've ever met because he has PTSD, too.
When you avoid looking into your own eyes in the mirror because they look just like your mother's and you will trigger yourself.
When you spend the majority of your time in silence.
When you really need to go to the store for groceries but it takes you 3 hours to convince yourself that you really should go so that you can eat because you've realized you haven't eaten in 3 days.
When your ex-spouse knew when you went to restaurants where you had to sit in order to feel safe.
When you have lived in a new state for 13 years and have not made a single friend in that state, so that all of your friends are long-distance.
When you can go years without talking with someone and consider that person to be your best friend, though when you do finally call them, you discover their number has changed, they've moved, and you have no idea where they are any more, or how to get in touch with them.
Or you do get in touch with them, and they say, "Who is this?"
Or you get in touch with them and find out that not only did they have 3 children since the last time you spoke with them, they are celebrating the birth of their 4th grandchild.
When your idea of a good time is to rent a movie from pay per view and sit home alone.