I'm hip to your observations, Andy. Some of my own:

What makes goose sh*t so slick?
Who "sees" me, who doesn't?
If they do, what do they think?
Why didn't I take a longer route?
Should I have ridden a different bike today?
Why do I always see men's underwear along the side of the road?
What are people in their cars talking about? Why are they on the phone?

Just a few.....