I just returned from a 7-day cruise on the Carnival Pride to the Mexican Rivera (ports: Puerto Vallarta, Mazatlan and Cabo San Lucas.) I'm 53 years old, my wife is in her early 40's and my daughter is 7. With us were my parents, both in their 80's.
This was my 6th cruise, all pretty spread out over a lot of time. But I did cruise on the Princess line Grand Princess ship to the Caribbean just this past Christmas. With me on that trip were my immediate family, plus my parents and extended family. It is easiest to compare that cruise to this one with Carnival as they were just 6 months apart.
My parents love to travel by cruise ship, and this was their 20th cruise (although first with Carnival... it was my first trip with Carnival as well.) We took Carnival largely on a travel agent's advice, an agent that my folks have used for years.