I don't know if just believing it makes it true. Surely the belief that something is true, when it isn't, is self-disillusion? Along the same lines as believing blowing ones self up, and taking tens of others with them will get them to heaven. Look where that got the world.

I mean no offence, but saying 'Believing something is true makes it true for that individual' sounds like a scapegoat. An easy way out from the admittance of reality which, for some people, seems too hard to come by because they cannot imagine the world any other way.
Is it my mistake, or did they have Columbus burned for treason?

If the belief of one person made it so, we'd have never discovered gravity, before everyone's belief in its non-existence would have removed it entirely, and the same for any other scientific discovery since the dawn of man.

I do agree heartily, however, that words are too restricting, especially metaphors, as they can be interpreted in any way. But either way, I stand my by first comment. If death realises your true self, you can be the first one to try it out. :P