I'd suggest connecting the ability to swim to what it means on a larger scale: how it contributes to our ability to learn, helps involve us in community settings, and provides a pause and release from stress. They're not things unique to swimming yet its something many individuals have in common, things that help build us up and keep us emotionally and socially healthy. You can choose to directly connect this to a childhood development or keep it to a more vague adulthood idea.
You could also go in a different direction (in my opinion much more boring haha) of the physical ways swimming is beneficial. Its reduced pressure on joints during a swim (low impact), how it increases motor skills, and reduces inflammation, all things which prevent the process of aging.