Conversely, a good, well-socialized older dog can remind a young dog of their "manners" better than any human can. I remember when Augie was about 6 months old and full of himself "fastest dog in the park" - he met Lady Quinn. A GORGEOUS blue merle Aussie about a year older than Augie - and he pestered her, poked her, barked at her....until she ran him down (effortlessly) and proceeded to "kill" him. This cycled a few times, until he finally realized he wasn't that fast/cool/fun; and he started treating her with kindly respect, at which point she began to play with him. That lesson stuck with him - he is pretty good about leaving elderly dogs (or ones with prickly temperments) alone. If a dog growls at him, he simply walks away to find someone more fun. That's a pretty valuable lesson, IMO.
He also makes a point to greet every human at the dog park - for a breed that can be somewhat standoffish - that's good socialization, too.
