Congratulations on 13 months. I'm at 18 and I still have them occasionally. The part that I remember usually involves holding or seeing a partially empty bottle or glass, and despairing that it's too late, that I've already relapsed and there's nothing I can do but start my sobriety clock from zero again. While I'm debating lying about having done it, I get a little panicky and wake up thankful it's a dream.
This isn't any more common than the old dreams everybody has about still being in college, late for a final exam, not having studied, etc. From what I understand about dreams, they are just your mind's way of processing the day's information, and that they have no real meaning, so I don't worry about it too much.