I Have Never Been Hurt By What I Have Not Said

Here’s a twist of quote I have found in my gmail. Calvin Coolidge quoted “I have never been hurt by what I have not said”…

It took me quite a while to understand what he meant. So he is always been hurt by what he said… I am thinking what does that mean… Are you not hurt by what you said? Or, are you not hurt by what you have not said? It is turning me round and round to understand this phrase… I guess logical people will start to get really confused by his brainy quotes…