We can see this quite clearly with traffic on the road. We stop and let some stranger out and they join the traffic flow. Then later when we need to make a turn onto the road, someone else – another stranger will let us in. Of course, if we have the ego mind-set and think: Why should I let him/her in? Then we know that further down the line no-one will give us an inch or a finger of help when we need some co-operation, no one will give way.