To address the original question, we brought some friends along on a New Years cruise with us a few years ago. The night before embarkation, as we were enjoying our pre-cruise dinner, one of our friends asked, "Which ship are we on tomorrow?" After about falling on the floor, I answered, "Vision of the Seas." He said, "Oh, ok. But what ship is that?" I asked, "What do you mean, 'what ship'? I just told you." He said, "Is it Carnival or what?" I said, "The cruise line is Royal Caribbean; the ship is Vision of the Seas."
What's really odd is that we had booked this cruise about a year in advance, and leading up to it, we were coaching the other couple regarding what to expect (one had sailed previously, while the other was a first-time cruiser). It never occured to me that he wouldn't know the ship or the line.
Regarding using a good TA, I have a short story about that. My husband and I were at a travel industry function and met 2 gals who were hired by a large online travel agency (you ALL know the website). These 2 gals ONLY sold cruises. We got to know them over lunch, and when I asked them how many cruises they'd each been on, they said NONE! Wuh???? How on earth can they ADVISE cruisers? These were just glorified order takers, apparently. I wonder if they're still with the company.