One of the easiest places to find them is in a hotel. Thus they carry the symbolism for richness and at the same time for the idea of not being too attached to one place. This symbolism also carries into the dream world somewhat too.
If you have a dream about double doors then this means that you have just walked effortlessly through into a new stage of life. A door represents an opportunity, and a double door set is known for being easy to walk through, you barely have to move at all, so if you have a dream about double doors then this means that you feel like you have just walked easily into a new stage of life and are ready for what this new stage might offer you.
If you have a dream that you are constantly going through double doors then this means that you feel well endowed with riches. You feel like you have succeeded in life and are now reaping the benefits of that success. You are a well educated person with elevated tastes and thus it is important for you to keep these tastes in check. Another thing that double doors might represent though is your inability to latch on to one person or one thing in life. Perhaps you are constantly moving, constantly switching partners, switching jobs and you just can’t stick to one. While this might mean that you get to go out more and experience parts of life that many never get the chance to, it also means you have nothing tying you down which can be quite unhealthy in the long run.