First, there’s this nifty little feature on cars that all the kids are using these days. It’s called a turning signal. You use it to communicate with other drivers! (Crazy, I know!) Gonna change a lane? Let others know by using the turning signal so they can help you get where you want to go safely.
Also, how about you check to make sure there isn’t a car beside you before deciding to change lanes! Even if you decide not to use a signal, it kinda keeps us from colliding.
But you shouldn’t have even been in the left lane to begin with. On long highways outside of cities you’re supposed to use that lane to pass other vehicles. You’re not supposed to drive in it then move out of it so I can pass you while I’m already starting to pass you in the right lane and so you almost hit my car, but don’t worry, I pressed my brakes to avoid the collision!
(P.S. This probably sounds incredibly more dramatic than it actually was. The incident really wasn’t that bad. I’m just playing it up.)