A dog may be a blank slate, but that blank slate comes with a whole box of colored chalk. Or big box of crayons. Once you get that waxy stuff on the slate it's going to be tough to wash it off anyway, to the mixed metaphor might be just better than I first thought.
When we're out, and he sniffs out some of his dog friends, he goes on alert. As much as a block away, it is tail up, ears up, and sniffing. Then, the tail starts to wag. Depending on which dog it is, the tail could leave a welt on you as it's a blur of black and white energy.
We approached our friends, dog and person. This time it was done quietly. Marc lives around the way, and is used to us, and our energy crisis. He will pet Rack, gently, and use quiet tones. The result is that Rack isn't jumping all over the place like a giant spring loaded toy. Sure, the excitement is there but it's manageable. Marc's dog is an elderly Dalmatian named Pepper. Pepper doesn't appreciate being climbed by an over eager puppy so she's getting wary.
The low, slow, and mellow approach is the way to go.
Dogs read your energy and body language. After all, while they may learn a few words, to a Dog, English or any other verbal language is an arbitrary construct. You can speak sweetly to a dog while saying obscenities and the dog will probably just wag its tail. Conversely, if you yell at the top of your lungs "YOU ARE A GOOD DOG!!!!", the dog will rightly consider you insane and try to run for the hills.
The nearest proper hill to me is in Titusville, Florida. That is about 200 miles away, so please don't yell things at my dog!
The second person we met on that walk did. He didn't scream at my dog but his energy and his high squeaky "little guy" voice got Rack bouncing around. He's got two Greyhound rescues, and I have never seen a Greyhound who was hyper. The two dogs were reacting to the energy exchange in an interesting manner. One was a step behind the other. That dog seemed disinterested in my own little spring, and was walking well behind the pack. He really seemed like he wanted to be "elsewhere". The lead dog was a quarter step behind his master who now was starting to make sounds like a whistling tea kettle. That dog wasn't exactly happy with the scene but was trying to make a go of it.
Once we finished with the excitement, I saw the results. The last quarter mile walk was me correcting Rack. He will normally walk slightly ahead, leash slack. Not now. My arm was being pulled due forward by a rigid leash. That won't do. The energy level was way too high as a result of the squeaking voice and energy.
High energy dogs can be amazing. Without that energy and "drive" you will have a lap dog. They won't be "driven" to do things like be sniffer dogs, rescue dogs, therapy dogs and the like. When was the last time you saw someone walking a Shih-Tsu or a Basset Hound as a seeing-eye dog?
If you wonder why a dog acts the way he is, consider what you're showing yourself to be. There's a reason why you have a Cheerleader at a sports event - they're trying to get the crowd "up". That's exactly the wrong type of energy to have around a dog, whether they're in training or not.
But, hey, who am I to judge? Some folks like crazy pent-up energy.