Where does it end?

So I'm just curious what's ahead for me. I'm the last 6 months or so I've come a really long way. Knock on wood, every session is a joy. And while I had some incredible experiences early on, I've settled into a pattern of simply wonderful experiences. Overall, while singular moments may not reach crazy new heights too often, an average, if you will, of each session, has seemed to slowly just get better and better. There are nights I'm amazed and just don't want to stop after what sometimes approaches 4 hours. 

My question is, does the experience ever plateau? I know every session and even every peak within a session can be different, but so often I'm amazed at the experience and how it just keeps getting easier and better. Having asked that, if I was stuck where I am today going forward, I would forever be satisfied. I'm just curious if you ever reach a point going in knowing what's ahead. I still feel like there is uncharted territory out there just based on how much I can currently relax myself and the point when my body gives in to what it's feeling - meaning I can't relax anymore. Is there a ceiling?