Having grown up in Miami, where learning how to swim is more important than learning how to walk, it still boggles my imagination that there are people who don't know how. I don't say that to insult anybody, because intellectually I know that there are many, many places around the world that don't have water around every corner and a swimming pool in every other back yard, but my brain still boggles when I encounter that reality.
Now, not liking to swim, that's a whole 'nother story. I can totally understand that. I prefer to stay on the shore more often than not.