See, the thing about Secondhand Lions and The Last Unicorn is that what's worth believing in is true, and what's true is worth believing in. The causation of this may work both ways, and the inverse remains-- if something is not worth believing in, it turns out to be untrue in the end. Perhaps everything sad is not coming untrue, not yet-- but everything hollow and ugly and worthless is certainly coming untrue.
You can choose to believe in whatever you want, of course-- just because something's not true is no reason you can't believe in it. But you can't make something into something it's not by believing in it; all you're earning yourself is an illusion.
Whatever something really is will come through in the end-- and the wondrous thing is that it works both ways.
Even if something's a kernel, a seed, of truth with something else built up around the outside-- even if someone is just a weary old man with only the air of greatness and goodness about him, even if a lion is just an old worn-out circus lion who's never seen a jungle, even if a human woman is only a human woman who can't even remember that she used to be a unicorn-- that truth comes out and its reality consumes everything else in the end. The stories about Africa turn out to be true; the lion does what only a real lion can do; and the unicorn, changed though she may be, is still a unicorn. Cinderella's ashes may give her her name, but they cannot keep her hidden from the prince in the end-- they cannot change what she truly is; especially since what she truly is is someone good and steadfast and worth saving. The kernel of truth betrays the whole.
