Fortunately, of late, I haven't had too much of a crowd during my swim periods.
Had a nice response yesterday from a swimmer in the next lane (the pool was uncrowded so we each had our own lane). The gent was doing a head-up Weismuller type stroke, and I was doing some 50s. At one point, while we were both pausing at the wall, the man said, "Wow, you must be a pro!" Well, truth to tell, Michael Phelps can do a 100 and then some before I finish a 50 (right now I'm chasing a "blazing" 55 seconds), but it was still a sweet thing to hear!
In between a couple repeats, I noticed that the man was trying to swim as fast as he could, and so figured he deserved some encouragement. "Not bad!" I said to him--and gently asked if he'd like to try it putting his face in the water--that it might make swimming a bit easier. Then I showed him the breathing. He said he hadn't ever learned the breathing, so was very appreciative and thanked me.
Fortunately, the sparsity of swimmers allowed for us each to do our own swim. I can feel as frustrated as anyone when I'm in a lane with someone who is unaware of pool etiquette and whose swimming style is incompatible with mine, but I'm grateful for experiences in which swimmers at different levels can give each other a boost. Heck, how many times does anyone call me a pro in the pool! And I was glad I could offer a little help to him.