> So many a young Lab will spend a while standing on the shore, watching humans or other dogs in the water, and fussing because they don't dare to join the fun. Then they may (for example) eventually lean too far and fall into shallow water. Within moments, they'll typically be swimming around and having the time of their lives.

Interesting, I didn’t know this was a common phenomenon! It describes exactly what happened with my childhood lab - my family would go swimming at the river and he would whine and fuss at the shore, until one day he wanted to play with another dog that was in the water so badly that he just jumped in, and was swimming around like he’d been doing it his whole life already.

Every dog does this.