Almost got into a car accident bc of pure stupidity!

So today I'm coming back from my drs appt and I'm just driving and there's this car in front of me. He's acting weird, braking for no reason, swerving a little. I can't get around him so I'm stuck. I stay as far back as possible. Well here comes the stupid part. He brakes and puts his left blinker on, mind you he's going like 25 in a 35 mph zone. I'm like ok great this idiot is turning, I go to drive around him on his right and he TURNS RIGHT. With his left blinker on. I'm not kidding! He turns into this Plaza on the right! I had to jam on my brakes and I was in shock. Idk what was wrong with that man but if you don't know your left from your right you should not be driving. Yikes!