I can understand how a person might grow up without knowing how to swim. Some may just never have been offered the opportunity to learn because of their location or lack of parental initiative. But in my opinion, swimming is much more than a survival skill, it is a life skill.
Both of my children began swimming at a very early age (the age when you have to shuck the diaper and worry about pool-poo). I did this because my parents did the same with me and my brother, and I've never had a fear of the water. Respect yes, fear no.
We did not have a public pool, but went to the mountains where I learned to swim in a stream (Sylamore Creek in the Ozarks). When I did later have access to a municipal pool, in one summer I went thru every swimming class they offered and, like the previous poster, got lifegard status well before I was old enough to be a lifeguard. My own father, a WWII Navy vet was my teacher and inspiration for learning.
Not only has my ability to swim stayed with me and been passed down to my children, it has allowed me a long life of enjoying watersports such as boating and fishing. Several times over the years, it has allowed me the opportunity to use my skills to save the lives of others. Many more times, it made a world of difference in how much I was able to participate in and enjoy whitewater canoeing and wilderness tripping.
I am always saddened when I hear about people drowning. Doubly so when the story indicates that even basic swimming skills would have made it a non-event.