Welcome to my world

My life has been reduced to waging a battle of wits against a 9-year-old, neurotic yellow lab.
For several years, we've been using old baby gates to corral our two dogs. The procedure was nothing more than a mild nuisance. And, until about two months ago, it worked.
Then, the universe shifted and threw our household's canine alignment completely out of whack.
One moment, the dog is merely borderline annoying, yet still endearing. The next, he is full-on paranoid schizophrenic, chased by voices only he can hear.
In this newfound desperation, he (the one in the back) figured out that all he had to do was push the gate until it crashed to the ground, leaving him free to wander the human world.
The problem hasn't been so much that he escapes, but rather what he does when he roams freely throughout the house without any surveillance.
Under our watchful eye, he lulls us into complacency and sticks to the dog bed or the carpet. When we're not around to know better, he skulks through the house, finding comfort on a couch or a pile of clothes in the son's room (which, I would say, is well-deserved since the clothes should either be in the dresser or hamper). In his wake, the dog (not the son) leaves a blanket of dog hair and dog stench.
We responded first by propping chairs up against the gate. It seemed like a reasonable measure.
But we quickly discovered, it was no match for the muzzle. Each night we would awake to the sound of a crashing gate followed by the skitch, skitch, skitch of doggy toenails on the kitchen floor, hightailing it for the great beyond.
Because man is always drawn to a challenge and can always build bigger and better, the husband made a seemingly more sturdy gate from leftover wood flooring. We fortified the new contraption with three chairs and went to bed reasonably assured of our superiority.
The next morning, our household awoke with an air of celebration. The wall stood. The dog was still in the kitchen. Seriously. This was a monumental achievement of epic proportions.
Unfortunately, we wouldn't know it for a few more days, but the jubilant moment was short-lived.
Several more weeks passed. Some nights, he stayed put. Others, he found the super-canine strength and agility to batter down the gate/chairs contraption.
"Maybe he really has thumbs," suggested one daughter.
We stepped back and reassessed the ground floor configuration of our house. Maybe instead of gating the dog into the kitchen, we reasoned, let's just gate off the rest of the house.
One gate blocked the stairs to the basement. Another gate cordoned off the stairs leading upstairs. I threw a third gate on top of the living room couch. The homemade fence protected the tv room.
Once again, we outwitted the dog. A week later, though, he stuck his damn nose between the fence and the woodwork to gain access to the tv room. We reinforced the fence with dining room chairs. He still managed to move the entire contraption with his snout.
Many people might have noticed the pattern, accepted defeat and given into the inevitable. Not me. I refused to wallow in the defeat of dog hair.
It was then that I spied a pair of 35-pound hand weights sitting on the floor. I put one on each chair. Hah! Try moving that!
It took a couple more days, but he did. It's got to be the thumbs.