Reality is a gradient phenomena that follows the general function f(A)=R where A is the degree of agreement between two or more points of view. Those things about which one has the most agreements are very real to him, while the less agreed-on things, such as the existence of Penelope Rutledge, Gluon, or Rapparree, are less real proportionately.

This general function applies to the physical universe, the universe of social agreements, and the universe of one's own created version of reality equally well. Don't youb agree?;>)