There is a theory called “seriality” which argues that dreams are composed partly of memories and partly of premonitions.
There is considerable evidence that at least some dreams are composed of what psychologists call “day residue”; bits of recent thought and memory from when one was awake. It can (and has) been argued endlessly whether the process of dreaming is somehow related to resolving conflicts arising from the experiences with which this residue is connected.
Although Freud is increasingly out of vogue, his explanation that dreams are symbolic representa- tions of suppressed conflicts still has some validity. Certainly some dreams seem to be about what Freudians say they’re about. An old joke: “I kept dreaming about a giant hot dog chasing a huge donut through a railroad tunnel. My psychiatrist said it means I’m obsessed with food”.
Then there are dreams which seem to represent perfectly conscious conflicts, and without any obscure symbolism. Years ago my church came into an unexpected windfall and the money was spent on redecorating the church. After listening to a discussion of whether the money should have been given to the poor or something instead, my father had an odd, vivid dream.
In it he won a lottery and he gave the money to our pastor to hold for him. Later he came back and asked for it back. He said he had the impression he thought the pastor was going to invest it or something, but instead he went to a corner of his office, pried up a floorboard, and fished out a wad of bills which he handed to my dad. As my dad was walking out of the office he encountered a bum who kicked him in the shin. For interpretation, see the parable of the talents.
As for religious interpretations, there are, undoubtedly, instances of prophetic dreams in the Bible, but Rabbinical writings support purely psychological interpretations too. For instance, Joseph was let out of prison when the pharoah learned how he had interpreted the dreams of two of his fellow prisoners correctly, telling one of them he’d be released and the other that he’d be executed. The phenomena of day residue was understood to some degree already, however, by the time the Talmud was compiled. One of the rabbis who wrote this work observed that dreams are composed of real things people have experienced, and added something to the effect that no man ever dreams that trees have feathers.
Since the future is composed of things like the ones which have occured in the past–and not made out of trees with feathers–it seems entirely possible that one could dream something which is similar to what will happen later, and only be thinking about things one has already experienced.
True, there was never an event quite like the ones on 9-11 before, but there were terrorist attacks before–including one on the World Trade Center already. There had also been spectacular airplane crashes before, some of them involving tall buildings. There had even been a discussion on the Internet months prior to 9-11 in which people argued how well a World Trade Center tower could withstand the impact of a 747. None of this proves that your dream was not a prophetic experience, but only offers the possibility that it may have been something far more mundane.