I have to agree, that when you are on a bike in urban 'warfare' traffic situations, you are in a constant state of heightened sense of awareness.
When I lived in the Chicago area, on the first ride of the season, you really weren't prepared for the onslaught of sensory input on the bike, as compared to driving a 'cage' for the previous 5 months or so.
After 16 years of riding all year long, I have forgotten what that first ride of the season was like !!!