Our 3 main reasons for choosing a cruise were: 1) Relaxation, 2) good food, and 3) experiencing foreign cultures. Unfortunately we did't get any of it!
Ad 1), The moment we entered the ship we found out that hundreds of young people were on board as well, and they had brought their own music, which they played loudly and constantly, especially around the pool-areas, so if you were more than 25 years old you'd have to go somewhere else. The noise continued into the evening and night when they entered the hallways, corridors and even pulled mattresses out on the balconies where they sang and shouted until the early morning. We had 3-4 hours sleep every night and after a few days we walked around like zombies and just waited for the trip to be over.
Ad 2) The food was absolutely appalling! Breakfast were 3 kinds of cold egg-dishes with burned bacon and some old bread you could hardly chew - unless you washed it down with a thin, tasteless substance they called coffee or various juices, which had never been even close to a fruit. Lunch and afternoon tea were third-rate cafeterias, and dinner was the worst we've ever tasted. Soup, fish, meat, pasta - you name it - were cold and inedible, so in stead of gaining several pounds, which we normally do on vacations, we lost them!