Generally it is better if you keep the conversation that you are having with yourself in your head so people refrain from calling you any number of names starting with insane, unless of course it is a very interesting conversation on a very boring rainy day where other mental stimulation is nowhere to be found and a crazy person is funny not weird. During these circumstances it is always better to overdo it so the general public thinks you are kidding.
You are not crazy if you are talking to yourself as long as you do not answer.
"MOM! Johnny is talking to himself again!"
"Dont worry about it honey hes got nothing better to do today if you want to start talking to yourself, i am sure his personalities wont mind."