I'm moving into a house (from an apartment) this weekend and I'm afraid that the same thing will happen to me.
In fact the very same thing happened when I moved here and started my job. You make an objective decision beforehand, carefully weighing the positives and negatives. But once you face the reality of the decision you made, I think it's natural for the negatives to stick out more than the positives (especially if you're a cynic like me).