I'll be honest... my husband is really bored on any cruise (prekids) and I was really bored on a
Disney cruise (prekids). I loved the daytime vibe on board, but the nightlife was non-existent for a nightowl. Carnival and RC had wonderful adult options late at night I really enjoyed. My husband is just not a sit around and relax person, and hates being in the sun. The pool is people soup.
But - that totally shifted when we had a child and neither of us were bored for a second on the Disney cruise with a toddler in tow. We wanted to do so many things with him that it was impossible. Wonderful family memories made so easy - just show up! Only preplanned the royal gathering and Palo dinner for our anniversary. This trip, we didn't plan anything other than Royal Gathering and hope to snag a Palo brunch on board. Such a nice change from the overplanning we often do at Disney parks! We did crafts, dance party, family trivia, mini golf, walking the deck to watch boats when near port, character meets, scavenger hunt, etc.
My advice is to not overplan (or overpack!) and create your own adventure each morning/hour with whatever sounds fun at the time.