two weeks ago tomorrow, I dislocated my collarbone in a full speed collision with an opposing player who was merely angered at the lack of points his teams had scored. he was very apologetic but it was a bit too late, I'm now out for about a month.
I play lock and I wear a scrum cap for two reasons: -
the main one being that I have a habit of pulling back out of a scrum very quickley and without a scrum cap my ears would be in a props pocket.
and the second being that it just gives me that slight added confidence I need to charge at some poor innocent center/fly half/winger/scrum half.
but I think that when I was young, my parents enforced certain safety on me, and when playing rugby that included a scrum cap. and now I can't get out of the habit of wearing one and feel vunerable when I'm not.