I think your underlying assumption is incorrect. I have always felt that this old meme about talking to yourself being a sign of mental illness was completely r

I think your underlying assumption is incorrect. I have always felt that this old meme about talking to yourself being a sign of mental illness was completely ridiculous. Perhaps taken to the extreme, where a person walks around all day spouting nonsensical gibberish to no one in particular may well be a sign of mental illness, but this is very different to what most people seem to be referring to when they think of talking to one's self, and obviously different to what you seem to be referring to, as your question revolves around the idea that people's use of Twitter is potentially just them talking to themselves and why this does not indicate mental illness. I'm sure there are some out there who do just type nonsensical crap into Twitter all day. It certainly seems to me that a great deal of the content that appears on Twitter is inane in the extreme. But none of this supports the underlying assumption of the meme, which seems to be that talking to one's self in any capacity is straying into the realm of mental illness. There is a large difference between the symptoms of mental disorder and having an introspective conversation with yourself, some or all of which may be spoken out in an audible manner.