If you learn how to build a castel with a very specific era look and feel as an architect, would you not then be likely hired to build a similar castel elsewhere?
But I've never built the exact same castle, with the exact same Floorplan, with the exact same plans. That's what I'm highlighting that I've seen several times.
A cool aside, I love this song by Watsky called "cardboard castles". Having done this for 20 years (build "cardboard castles") I identify with it.