Wonderfully simple, and tells a complete (if somewhat vague) story. The vagueness is a huge positive. Lets the listener "fill in the blanks" and adapt the story to his/her personal experiences.
You have provided (imo) a perfect blend of "complete story" and vagueness. That's REALLY hard to do, and you really nailed it.
Without knowing the exact story behind this, I totally identify with the protagonist/singer/writer. One of the best lyrics I've seen here I think.