I rode a cruiser on Hilton Head Island, on the beach. Was great when going with the wind, not so great when I had to ride back! My knees hurt for 2 weeks after that.
When I went with DH to buy my first road bike, I had been riding a modified mountain bike for almost 2 years. I was fit. The first 3 bikes the guy brought out to show me were flat bar road bikes/hybrids. I said to him, "What part of road bike don't you understand?" All of those flat bar bikes were nice, but not what I wanted. He made a lot of assumptions.
I refused to go to Landry's for anything after i made that purchase.