DH and I are both 35ish, childfree but "quiet people". We love to get up early and go to be early, we don't like going out in bars... We love
DCL.
When we cruise, we like to take advantage of the adults only sections on the ship (Quiet Cove, Cove Café, Palo --dinner & brunch-- and Remy) and at
Castaway Cay, we spend 99% of our time at Serenity Bay which is the adult only beach. We always ask to be seated alone at the restaurant.
At the port of calls, I would say most excursions are suited for adults.
On the cruiseship, we have appreciated the mixology class and From stem to stern wine tasting which was really interesting. We also appreciated The Golden Mickeys (show) which suited a bit more to us as adults than the other shows.
We also really enjoyed the movie theater and found that there was a good selection of Disney Movies (Like Antman, Inside Out and The Good Dinosaur... Which in my opinion, can be appreciated a lot by adults).
Also, although we did not spend much time on it, we appreciated having a verandah. It a very nice way to relax and stay away from the action. When the cruiseship leaves PC, we do not go to the Sailaway Party, we look around and try to locate/watch dolphins swimming behind the ship.