GenePoole, I personally find that I no longer have that honeymoon phase. Admittedly my relationships tend to be a bit more casual however I would say that the "honeymoon period" comes from the euphoria of learning about somebody. Then you get to know them and become comfortable.

I tend not to get into the comfortable stage, you need to keep trying new things, surprising them and if I find they can't keep up or just want a humdrum existence I'll tend to leave them to find somebody who wants to give them that.