Yes. But which stimulus? It's certainly not directly and neccesarily related to making muscular inroads, otherwise everyone (who works out with the same intensity) should be sore after their workouts. I, for one, am not. That goes for others too. Not unless the exercises haven't been done in a while, or perhaps not in the same way. Some do feel sore on a regular basis, apparently. I can't speak for you, nor can you for me. But if soreness indicates progress then I must not be making progress. But I am, and I don't feel soreness. This is a sticky subject as has been noted.
The reason you are sore is because your body is adapting to the new load or stimulus.