Most of the lines are quite funny, but this one could actually be quite insulting. A person who does not have any experience of flying may not immediately know how to work and adjust a plane. I know a couple of elderly people who have never driven a car (so little experience of seat belts anyway) and who have either never flown or only done it a couple of times. I suspect that they may be slightly unsure about using the belt, and certainly incredibly insulted by the insinuation that they are unsuitable to be out in public unsupervised.
Originally posted by Paul Wheaton:
8. From a Southwest Airlines employee: "Welcome aboard Southwest Flight 245 to Tampa.. To operate your seat belt, insert the metal tab into the buckle, and pull tight. It works just like every other seat belt; and, if you don't know how to operate one, you probably shouldn't be out in public unsupervised."