There's something eerie about the entrance lobby to an apartment building. One opens the outer door, walks past the mail boxes, opens the inner door then goes up to one's apartment. If one does this every day, it's easy to not even notice. Once in a while, one does notice; then it becomes vivid, sort of like the magical feeling one gets on returning home after a long absence. It stimulates the imagination. A key to imagination is to pause for a moment and notice what is so familiar, one often doesn't notice. Of course, in order to stay focused on a task or sequence, it helps to tune out what is not related to what one is doing. To concentrate on a book, one might try not to hear the quarrel going on in the next apartment, or the blower machine and street sweeper outside.