I remember my neighbor's dog who kept barking at everything that moves, and it just barks and barks and barks, even late at night. Its annoying but what else can I do except to put up with the barking.... Because life goes on and like it or not, we all need some sleep sometime (and like it or not, I have to sleep) and after a while, we got use to the barking and it became part of our "night time music".
And sometimes, after a while when the dog decides not to bark, we wonder what had happened and missed the barking.....
Heh.... Life goes on mate!
By the way, the neighbor finally moved..... :)