That's my point too. I believe it very unlikely to have turbulence for the entire trip. It can be alarming if it's your first time experience serious turbulence. I was on a flight in the 80's on NW; the plane dropped maybe few feet--probably just one or two. The attendants were serving at the time. The cart and attendants just went in the air, then dropped down. No one was seriously hurt that I recall, but people were shaken. From that time, I always wear a seatbelt when seated.