In my view, that can go either way. Sometimes we expect a change in external scenery to change us and, after the novelty wears off, find ourselves in the same state as before. Emerson said that travel narrows the mind; I suspect he was talking about something like that.
I have always thought travel is more than a change of external scenery. Travel forces you outside of your comfort zone, away from people/places/things that are known.
It depends where you go. Travel makes you pay attention to your surroundings. It also forces you to let go of certain things, and concentrate on a whole new set of issues, like "how to get from point A to point B", or "where am I going next."