Have you noticed how friendly children are? If they know they are safe they will usually try and find out who you are and what you do. They are more open and want to know more about the world around them. Somehow when we grow up we are more careful about who we speak to, we have opinions about what people are like even if we have never spoken to them.
We need to be more open and friendly to those around us, we still need to be careful, but a smile or wave to a neighbour can make all the difference, particularly to someone who lives alone and may not speak to anyone at all during the week.