A Regent voyage is not only the ports. It is the mornings with nothing in the diary, the lunch that turns into an afternoon on deck, the lecture you wander into because the subject sounded interesting.
Those days are why the ships are built the way they are. Few enough guests that the pool deck never fills, a spa that draws its treatments from wherever you happen to be sailing, and six restaurants to move between with no set times and no supplement to pay.
By the time the next port appears on the horizon, you have already had a good few days. That is the part most people remember.