Romance, the best joke ever told in this world. John knows a thing or two about romance. He is, after all an idealist, and what can be more utopist than romance. It's basically something that only lives in one's head, and because our John is nothing more than a shadow in a head, romance lives in him. He feeds from it, the same way he feeds from the pain. Because pain is nurturing for a romantic, it's the only possible outcome of love, and so it must keep flowing so that love can keep existing.
Actually, pain is the way that John's idealism materializes. He's a ghost of love, and pain is what happens when he tries to escape in reality. Because love can't fully conjure in the real world, it turns into pain instead so that the ghost remains a ghost, so that it doesn't become real. After all, who would want the ghosts to become reality. Just imagine how fucked up this world would be if out of nowhere all of our ghosts would start to take shape and walk with us, follow us like minions everywhere we go. Not to say that the world isn't fucked up anyway, but that's another story. Think about it. Think about walking down the street and seeing every John Doe, everyone with a story. " I'm John's lack of self--esteem, pleased to meet you, would you like to walk all over me?". "I'm John's hopeless romance, would you like to break me up into pieces and feed me to the dogs of hate?".
So yeah, it's better that John remains a ghost, that all the Johns and Janes are ghosts. They follow us everywhere, but no one else can see them, no one to bother them, no one to feed them or crush them. John is free to live his pitiful inexistence in peace. And so is Jane. And she always was, just like he's always been. Both free ghosts trapped in two heads, both the same and at the same so different. Both wanting to break loose, still both fighting their way back inside after every little breath of air they get accompanied by a merciful slap on the face by the stone cold reality that they so desperately trying to reach.
Oh, Jane Doe. The one. The first one. The only true romance in John's existence. The one that brought him to life and then gently killed him as an act of kindness. So much to know about her and yet so little to say. And even less ever said. A love unknown by her, a selfish love, John's first love. She never knew, and she never will, because John could never be as brave as to confront his maker in the first place. And yet he misses her. He misses himself too. The old John Doe, the primordial one, he wishes he could go back to that existence, when he never even dreamt of the real world. Everything was imagination, and it was the best love story of all.
Just take a moment to consider. What better than to have not one, but a thousand outcomes to a billion scenarios and to be able to live them over and over again, without ever knowing how any of them would end in the real world. Just the purity of a sick imagination. The real world spoils the romance, and Jane Doe remains until this day the only true, idealistic, utopist and inexistent love of him. It may have been the most selfish romance of all, but John Doe deeply misses it. He just wishes he could go back. He just wants to be selfish at least once more in his life.