Here's how we count people on the Upper East Side:
The three of us reached the Park Avenue median at 76th Street just as the light was changing. The older gentleman approached slowly from the west, using a cane. The older lady approached from the east, being pushed in a wheelchair by an attendant.
The attendant, of course, is not one of "us" and therefore there are only "three of us," not four. (From today's "Metropolitan Diary" feature in The New York Times, which always says more about the city than I think the Times intends it to.)