How do you figure

I walk when I can't stand being indoors any longer, when the sun and cold breeze in the window gets too enticing, up against the stale temperature controlled air and manufactured bliss. I walk when I can't handle not walking anymore. It doesn't matter what time of day or night or what the weather's like. So how is it then that I keep running into the same person, in both work and civilian clothes? We recognize each other but have never talked or exchanged names. Why are these people in our lives?