I still experience highs, they are just of a different more subtle nature, but they are there all the same. Just harder to pick up on.
I also can address my need for adrenaline rushes, even better in recovery, because I have better control of my physical faculties. I ski better and faster because I have true confidence instead of bottle false bravado. The same for riding my motorcycle.
Scuba diving while not an adrenaline rush is still more intense because I am more fully present. Basically the highs are there, when I am fully present, instead of when I am looking for something, because in looking, I go right by the present.
Standing in the early morning rays of the sun in the back-country on top of a 12,000 ft mountaintop without another human being around for miles after a hike from my overnight base camp, is a high!
I used to pooh-pooh stories of people's burning bush experiences. I am now of the belief that I have been singed by many burning bushes in my life, I just wasn't present enough to realize the existence of the burning bush.
The highs haven't gone anywhere!