I rode my bike often in heavy Houston traffic many years ago but have only been riding regularly for the last few months.
The following info helped me to better understand the risks of cycling.
http://www.kenkifer.com/bikepages/health/risks.htm
Now I feel like the aircraft pilot who has about 700 hours - which I believe is a very dangerous time for a pilot. Getting a little cocky, too sure of one's self, no longer as worried about the dangers. So, I'm back to concentrating on safety, but I don't want my perspective to become overly fearful either.
Glad you were able to hold your line when the truck went by.