Not even that. There is really nothing to discuss if the only thing I believed is that I exist, and anything else is potentially a hallucination. Even p ^ ¬p could be true, perhaps I'm just hallucinating the rule that says it isn't.
In a way yes, your whole reality is your own internal hallucination, and there is no way to break out of it
That doesn’t mean you can’t explore anything within that
In fact a lot of eastern philosophical and religious traditions focus exactly on that, how exploring your inner self is a valid and very good way of discovering reality
Not sure why you fixate on “nothing to discuss” or “conversation ending”
Neither the ideas above nor solipsism are dead ends, there’s plenty of exploration to be had within those
Now if you don’t like them or want to dismiss them, you are free to do so, that’s your own personal take, but that’s not an objective absolute truth
https://news.ycombinator.com/item?id=37721284
You might not like it and prefer to focus only on the models and the math
But fundamentally, all of our knowledge, including physics only really exists in our consciousness
You might also not find it useful, but that’s your own personal subjective opinion, not a universal objective truth (same goes for anything I’ve said)