Differ

I wonder if this sort of thing happens to everybody. Well, now that I really think about it, I guess that it does. But for some strange reason I can't figure out why it would happen so often.
Why is it that things turn out to be so different than we once thought that they would be? How is it that we can get past them and like something different?
Things that I felt so sure about only months ago are comepletely different than what I think now. It's strange, though- my old thoughts are still there, but they're...twisted, somehow. The same thought, just mutated into something else. Is this supposed to happen often?
When I ask myself what I find different, my answer is that nothing is different, yet I know that somewhow it is. My problem is just trying to find out what I'm really looking for now.