Everything really. But mostly an ally against emptiness and ennui.
If a Djinn were to appear to me and grant me the traditional three wishes, I would first ask him to materialise a hippo in my bathroom, then having satisfied myself that there was indeed a real live hippo in my bathroom, I would ask him to remove the hippo to a more hippo friendly environment. Finally, I would ask him to introduce me to the last person he had encountered who had wished as frivolously. For they would probably be my ideal partner.
As well as making a long held dream come true, that transitory hippo would remove the very foundations of my belief system. For much as I’d love to see her munching her way though a bath full of cabbages, for her to be magicked up out of the blue to do so would break every law known to mankind at some extremely fundamental level. Not so frivolous now, you realise? That I would have had the concern to care for the hippo, whilst in such a state of shock at the collapse of my universe is also of fundamental importance to me. (Although, even at the end of one’s world, one and a half tonnes of angry and confused herbivore is hard to ignore.)
To be more interested in questioning one’s universe than in feathering one’s tiny nest is the quality I value most in myself and others. To do so in ways that are creative, considerate and mildly crazy is the only way to cope with the fact that in reality, life is more complex, absurd and depressing than any mythology we have ever invented.
If you think this is hopelessly idealistic then you are almost right. If you think it is irrelevant to foundations of a relationship, you are very wrong, and haven’t considered the implications such thorough-going idealism would have for it’s holder. At a fundamental level the world makes perfect (if complicated and imperfectly grasped) sense and yet at exactly the same time on anything other than a human level it has no point at all.
One can escape (temporarily) from the dynamic conflict between these two perspectives if one cares enough about significant others, but if they are truly significant then you will want to share these uncomfortable truths with them and will want their obsessions to be your obsessions. To reassure each other that life isn’t so cold and empty after all. That is why it is essential that we share these foundations.. anything less is skating on the surface.