one of my favorite topics. if you're not up to speed, you'll get it from context, check it out.
okay, so anyone who's spent any time around neurotics, chilly intellectuals or the relatively jaded is familiar with the problems caused by encephalization of emotion. the more that pesky forebrain is involved in feeling, the less we seem to actually feel. this is basically the essence of intellectual detachment, and it's more pervasive than is immediately apparent. its inverse is, of course, stupid emotional people who can't control themselves because they stop thinking as soon as anything happens. consider the violent drunk for example.
anyway, think about infants (if you're comfortable with that). when they're happy, its the coolest thing in the world to them, and when something's wrong it's never ever been so bad. listen to those buggers scream: that must really suck. the point is, that lack of a developed forebrain means there's less blunting of emotional impact. think about how happy a happy dog is.
on to the metaphysics. a common claim among mystics and hippies is that the universe is constructed of joy and/or love. they talk about the ecstasy of unity with creation and stuff, reminding some of the 'God is love, becoming one with God is joy' thing the more respectable portions of society go on about. we'll get back to that.
anyone who's pulled it off knows that when things are going all right, it feels good to simply be yourself and do what you do. normals call this a hobby, i think. the point is that we can assume without the filtering effect of our frontal lobes, it would feel even better (incidentally, those who have never enjoyed being themselves may assume that you will not really relate to this stuff, and may be advised to spend your time more productively than continuing).
so if we assume that everything in existence is actually sentient on some level (and you'll just have to trust me on this one if you personally haven't ever related to an object), and that our complicated form of consciousness inhibits us from fully enjoying being ourselves, and that things like rocks and nebulae wouldn't really have that problem so much, we can see exactly how one would cobble together something resembling an explanation for the much more convincing experience of trippers and religious-revelation-havers alike.
informative?