I felt my first earthquake about 9 years ago. We were living in San Diego at the time and I wasn't sure what was going on. It was a loud earthquake - a deep rumbling - and woke me from a sound sleep. It was over before I knew it. The second earthquake I felt happened while I was Christmas shopping with my kids in a bookstore (not a good place for an earthquake). This one seemed to last a bit longer and I had enough time to register what was going on and get my kids away from the books and under a doorway before it ended.
I think when life throws you a major curve ball like a serious illness, a death, a sudden job loss - things of that nature - you just react. You hold on with both hands, try to do what you can to protect yourself, and ride it out - like an earthquake. What really gets you though is the aftershock - the sudden realization of what just happened. When you make it through to the other side you start to reflect on the reality of what you just experienced and it becomes more real.
I have a few "cancer friends" who have told me they can't quite shake the fear of what happened to them even though they are fine now. I also have a good friend who recently went through a whirlwind of diagnosis, surgery and recovery with her son and expressed the same thing.
Perhaps the courage and strength that people admire when anyone is going through a tough time pales in comparison to the courage and strength needed to move on. This is the silent strength - the one needed when everyone else around you has moved on knowing you are OK - and you are left alone to reflect.
I, myself, did not experience this kind of aftershock. Maybe it is because I was so reflective during my experience or maybe it is because I am not one to dwell on the past - but I don't think that is the norm. I believe most people have a much longer journey recovering from trauma than we expect. Next time you see someone who has been through the ringer and has come to the other side you might want to just check in with them - give them a hug - and let them know they are still in your thoughts. It might be just what they need to carry on.