Reoccuring dreams?

What are some of your reoccuring dreams? What causes them?
One of mine is a vivid dream from my perspective ( not a third party's), it involves a staircase- wooden, slightly creaky, incredibly detailed. Sometimes I'm climbing, sometimes I'm descending, on occasion I fall. The staircase is always identical- even the little rugs on each floor and the small ceramic vase containing poinsettias... Does this have a hidden psychological meaning or is it coincidence that it's in my dreams- I've never seen this staircase before...