I didn't think I had written anything complicated either. Shows how wrong we can be!
I thought I had quite a good example with that gardener and his flower to show how deciding which is responsible for its growth depends on what point we want to examine.

As for the excluded middle: It is whenever you are given a list of choices as if it is complete, but there are others that are not presented. If BillD turns up I am sure he can give a fuller and better account.