Mr. Knot's neighbors

So there is this man named Mr. Knots. He has three neighbors- A couple, a dog trainer, and a blind man. One day, he was taking a shower when the door knocks. He puts his clothes on, and opens the door. It was the dog trainer. He said "Congratulate me, I've trained my 100th dog!"So he congratulates the dog trainer, and goes back washing. Then, there is a knock on the door. So he puts his clothes on, and meets the couple at the door. The couple say "Congratulate us, we've just been married!"So he congratulates them, and goes back to wash. Then, for the third time, someone knocked at the door, interrupting his bathe. Guessing that it was the blind man,  he didn't put his clothes on, and went to the door. As he thought, it was the blind man. The blind man says "Congratulate me, I'm not blind anymore!"