I've been told to write nonsense, so here's some.
Solipsism is the belief that everything exists only in your imagination. The phrase 'extreme subjective idealism' has been used. Now, if I subscribe to this view, it follows that you're not actually there reading this (which may well be true judging by the number of visits I get to this blog). But you'll be thinking the same thing about me.
It's an interesting idea, but it doesn't really hold up. Why would I go to all that trouble?
So, here's the joke. A conference of solipsists is presented with the following agenda item: 'Discuss.'