When you're on a bike, you're IN the world, not just viewing it.
My outgoing 4-year-old says hi to everyone as we ride by them. It's his (and my) favorite thing about the ride to and from preschool.
I'm sitting here along the trail with my cargo bike interacting with my daughter and I see a guy with two kids ride by on his Urban Arrow, having a conversation with them, and he sees us and gives a wave. God I love this aspect of connectedness through transportation!