Reality is what we see, hear, smell and perceive. Tell me, do you perceive? Then your senses tell you what is around you. Would your senses lie to you? Why would we be in a hallucination? And why should we care? There's no way of breaking out.
Let's say this. A=The world we perceive. B=The possible "real" world that we do not perceive. Now, we do know that A=A through normal perception. We do not know if A=B, cause we have no concrete evidence that B even exists. But we have no evidence that disproves it. So we do know that A exists in our perspective which we all share (if A is the true one). And since we have no knowledge about if B even exists, why linger around it? We can either think all life about what could be, or look around and use what we see that we have in our own reality. There's no point in thinking about it. A could be equal to B, but we have no use of it, since we can't reach B. However, we can still believe that B exists(I like to believe that "B" is the alternate universe of God), but since B is outside our reach in A, we might as well just accept A until we die, and see if B is real or just let our atoms fly through cosmos.
