Over Reacting Or Under Reacting

Do you ever wonder why we act the way we do sometimes? I do.
I have an odd reaction in times of crisis. ( When I say crisis I mean a real crisis, not something that I've blown out of all proportion like a girl dumping me or something.) I seem to have a delayed reaction to what's happening. I tend to become almost detached.
For example when Ethan was born I was worried at first that I wasn't feeling the way I should. A friend once described seeing your newborn child as instant love. I wasn't quite sure what I felt for Ethan when he was first born. Everything was so hectic. Every member of my family at one time or another cried when he was being airlifted away. As the helicopter lifted into the air with my son I knew if I lost it, Angie would be even more upset then she was.
It wasn't until a week from that Friday when they told us Ethan was going to be ok that I let myself feel anything. The result as Angie and I walked though the mall was me almost dancing in the air. Angie still tells me that it's the happiest , goofiest , and silliest(is that even a word?) that she's ever seen me. I wanted to scream out to the world that my son would be ok.
On the reverse side was when we had the fire 10 days after Angie and I married. Angie lost it so bad when the fire broke out I didn't see her for hours afterwards. Later I found out she went to her Grandmothers house. She sat in her kitchen just shaking like a leaf. Meanwhile I was perfectly calm . I never cried or acted unduly emotional while I walked though the wreckage of our home. I didn't lose control during the 9 nights I stayed at my sister's house. It was only after we had a new apartment and were moved in that everything hit me. Sitting alone in my new living room I began to shake very badly. I may have even have cried a bit. I was just relieved that my family made it though everything ok. I thought to myself ,"Boy I never want to go through that shit again."
Even when I was four and in the Emergency Room for slicing my arm open I was very calm. I remember the Doctor telling me he wished all his patients were as calm as I was.
I have no idea why I do this. I wish I did.
I also wish I could have acted the same way to my own little personal crisis's when I was younger. It would have made my life a lot easier.