Why?

"It's comforting to know that he will have something tangible to show for those years, but more profound is the realization that a dream can die — any dream can die — and you can stand in that barren place in the weedy garden of your own life, amongst the sagging, withered plants, in the company of your own naked soul, and if you study the ground, you might just spot some fresh green shoots pressing through. You know yourself better now. You can begin again."
"On the Death of Dreams" by Jenny Schroedel

This is a really profound paragraph. I linked to the article, and the author has some good points. Sometimes, it's best to move on, and you may wonder what the point was or why God allowed something that did not ultimately come to fruition, be that a job, career goal, relationship, etc., but even if you don't know why, it doesn't mean that there wasn't a reason or that God can't use it for good. God does not answer the question "why." It's the one word He hears the most, but He doesn't often answer. He may reveal a reason later, but He may not. All we can do is trust Him and do the best with what He has revealed.