It's amazing how important those small subtle things can do for a kid, fair enough you didn't pursue swimming, but you pursued other sports and to a high level, yet that little act of kindness has stayed with you all these years.
There's a lesson there for us all, that it's not all about 1st, 2nd, 3rd etc, but moreso about each child and what it means to each of them, especially when they are young and so impressionable. One disparaging remark or comment can put them off a sport for life and equally acts of kindness can do the opposite.