Not trying to be snarky, but it might be that I don't get what you mean: I just look at the street name, which is posted on every street? I've never been anywhere that has no address at all, but I guess in those situations it wouldn't make any difference if I only knew roughly (like when I'm camping?).
How would you always know your current address? I often use maps with gps to find out where I am. Many places have no address.