Cycling aggressively doesn't necessarily mean you have a moral failing, or a death wish, or that you're foolhardy, or over-competitive.
One thing that's easy to forget is that cycling makes your body produce adrenaline to help cope with the physical demands. We seldom take into account what all that adrenaline does to our thought processes while we're under its influence.
This is well stated. I am also 59 and have noticed that riding can bring out the hothead in me. It's always fun to nourish the adrenaline - competitive side while climbing a hill with a chasing cyclist behind me or in some other safe way, but I see a big need in myself to not "believe everything I think" when negotiating with motorists. This is hardest when on an unfamiliar route, since I develop protocols for dealing with each intersection on my route over time as I recognize driver behaviors and adapt to them.