Swimming is nice for exercise! It's the self-propulsion of oneself through water.
It really is. I like to swim on hot summer days. It is so refreshing.
It is refreshing! It's one of the top public recreational activities. In some countries, swimming lessons are part of the educational curriculum. 
I think it's very important for kids to learn how to swim as soon as possible. There are too many drownings every year!
Yes, it is important. Because some think that babies are born with the ability to swim, because they have reflexes that make it look like they are. 
Yeah, I understand the evolutionary need for babies to be able to get out of water as soon as possible.
Yes, they need to get out because babies aren't old enough to hold their breath. And they aren't strong enough to keep their head out of the water!
That is very true. Kids don't have the motor skills to skill until they are about 4-5 years old.
And different people have different motorl skill depending on their own circumstance. 
I learned when I was about 7. I am sure glad I did!