Amen. This is why I use my turn signal when changing lanes every. single. time. Over 20 years and counting without an accident.
Be glad you don't live in Texas, where using your turn signal is tantamount to issuing a challenge, and is seen as aggressive behavior: "Oh, you want that right lane? No, it's MINE!"
Or worse, people don't see turn signals enough to know what they mean, and just adds to the confusion.