Why you never tell Nestle she is a good dog

I took Nestle to Petco last week. I don't know that I've ever taken Nestle to Petco. The last time I took Chaco, he decided to mark an end cap of treats. In fact, it was several days before Joe brought Nestle home from the city shelter and we were picking out a collar, leash, food bowl, and toy for her. Chaco wasn't happy. Anyway, I had to get food for them and had one other errand to run. We stopped at the vet clinic first where I took Nestle in and weighed her. She's still 73 pounds which was a relief since I was worried she was looking a little round. She did really well at Petco as I maneuvered the shopping cart and her around the store. She was quiet, too, which is a major miracle. We got to the cashier and waited for the people in front of us to finish. She was standing by me, sniffing a little bit but not too interested in what was there. And that's when I mistakenly said, "You know Nestle, you almost are acting like a normal dog today. Good girl." Huge mistake. She grabbed a treat out of the bin she could reach and dropped it on the floor. So much for my normal dog. When I ask her to sit at home to put her leash on, I can't reinforce her as I'm doing it and tell her she's a good dog because she'll immediately get up and start running around again. Nothing about Nestle is "normal" but I suppose that's what we love about her most.