Wag more, bark less
It's a good philosophy for more than just dogs
Not too long ago, I spotted a bumper sticker that said in large print "Wag more," with, beneath that sentiment in much smaller print, "Bark less." The same car also had a bumper sticker that said "I (heart) my Golden Retriever" – a breed that is particularly well-known for being friendly.
Cornhusker and Bassmaster have a Labrador retriever, Bo, who embodies that sentiment. When he wags, it's not just the tail; it's the entire back half of the dog. When a person approaches, even a total stranger, Bo exudes enthusiasm, as if he's greeting a lifelong buddy. He's not exactly a great watchdog; he seldom barks, and if somebody is willing to go a few rounds of "fetch" with him, that makes his day.
Dogs do such a great job of being joyful, and retrievers do it better than most breeds. Bo goes even beyond what most retrievers do.
Even though humans don't have tails to wag, the world would be a much better place if people would follow the sentiment on that bumper sticker. Be joyful, and celebrate the moment with whoever is around to celebrate with, instead of griping and complaining. You don't have to go chasing a tennis ball; just savor the time you have with your friends.