For the Lord your God is bringing you into a good land, a land with streams and springs and fountains issuing from the plain and hill; a land of wheat and barley, of vines, figs, and pomegranates, a land of olive trees and honey; a land where you may eat food without stint, where you will lack nothing; a land whose rocks are iron and from whose hills you can mine copper.
I wonder if this is a general phenomenon: you have been traveling for a long time, and cant wait to get home already, imagining all the warm, familiar, comfortable surroundings to which you long to return. Then you get there, and it is great. But in short order you are reminded of the annoying things about home that you had selectively forgotten the little physical discomforts and human annoyances that, on some level, it was a relief to leave behind. Or a corollary: you are really anxious for the kid to come home from college for vacation already; you really miss him/her. But it doesnt take all that long after arrival for both sides to remember nostalgically the freedom of the empty nest and bachelor apartment, respectively Absence makes the heart grow fonder.
And so as long as Israel was the promised land promised to Abraham, to Jacob, to the freed slaves in the desert, to the exiles in Babylon and Rome and points west it was (and is) a utopia of mythic proportions. Flowing with milk and honey, inhabited by a kingdom of priests and a holy people, the place where Gods presence dwells, and where everyone sits under his/her vine and fig tree with none to make them afraid, where we can be 100% Jewish. The farther away we were from it and the longer we had been gone the better it looked. And even in our own time, it is often more comfortable to live with a mythical Israel built upon our vision of how we wish the Jewish state would be than to live with the sometimes difficult reality of a real state inhabited and led by real people in the real world.
Over and over the Torah says and when you come into the land, you shall In other words, the Torah is setting forth an entire legal system in the vacuum of the desert, aimed at implementation in the future, in the land we havent yet entered and the state we havent yet established. And the descriptions of the land are similarly imaginative. Looking from the desolation of the Sinai desert, any green will do. The bit about iron in the rocks belongs with the petroleum reserves we dont seem to have. Indeed, maybe the real reason Moses wasnt allowed to enter the land of Israel is so he wouldnt be disappointed. After dedicating his life to bringing the people to the land, imagine the crushing reality shock of his discovery that no, not really any iron, and actually, in a dry year we would have to import grain Better to die happy in the desert with the image of the ideal state in the ideal land dancing before his eyes.
So maybe our repeated separations from the land and the memories of them have a positive purpose. Maybe they come to keep the dream alive, to pull us out of complacency and provincialism and the routine of normalcy. If we were just like everybody else, naturally, eternally, unremarkably planted in our homeland then we would be, indeed, just like everybody else. And that would sort of defeat the purpose of the whole amazing enterprise of Jewish existence.