“Reality is that which, when you stop believing in it, doesn’t go away.” Great quote. So great I even posted it to my twitter account (my other bookmarking service) But the paste dropped the end quote mark and added a comma to the front. HN did not and did the above paste just fine. It bothers me, and I don't know why.
Because our mind evolved as a tool for survival of our self which is to say as a tool for survival of that which may pass on the genes which create said mind.
This mind is, by default, full of illusions, full of a particularly biased view of the world and the content of that view does not go away when we stop believing in it and looks to us just like reality.
This is the whole point of meditation, but even if you do not believe in meditation yet, it can be observed in yourself and in others.
In short the statement is only true for the rather small subset of things that can be scientifically investigated and on that level beliefs are not a category of concern anyway. It‘s a statement about the content of the world without an observer, but the observer-world interface is the more interesting part, the observer cannot be removed and any beliefs come from the observer in the first place.