The marriage would only work if the "lower limit" one can accept is considerably lower, with a reasonable margin (or aka "common ground"), than the "upper limit" the other can reach. The bigger the margin, the more confortable the life. If the margin is too narrow, the relationship can be fragile. In LZ's case, the margin is negative, and hence the relationship has no hope -- so what's the point to fool yourself only to die a slower death?