Does the average person notice people on the phone or is it something that cyclists get used to looking out for? I also notice people not using a seat belt too. I don't know if I subconsciously look out for people displaying those behaviours and expect their driving to be worse or if your average person in a car/pedestrian notices them as well?
I suspect we notice it more for a couple of reasons. 1. we're more aware of the effect of bad driving and how it risks our personal safety, and 2. we mix more with drivers on the road, we get closer to them than the average pedestrian, and we're probably within sight of each driver for a bit longer, since we often leapfrog them in traffic, or have them in sight for longer than just a second as they whizz by. Also, we're more often alongside them, rather than sitting directly in front or behind, which makes it easier to see.
I saw a guy sucking his thumb the other day!