Trusting your mirrors

After a few million miles driving with mirrors I get a laugh out of people craning their necks or bobbing back and forth trying to see behind them. Take a few minutes,parking in a parking lot, grab something bright like a traffic cone or get an assistant to stand in various spots so you know where you can’t see, adjust mirrors accordingly. Watch a vehicle in your mirrors on both sides as it passes to know if you have blind spot still and add convex mirrors or adjust till it’s gone.Your own vehicle never hits you, and you don’t need to spot for airplanes so aim at the ground and away from yourself. Defensive driving is always having a mental picture of what is around you at all times, yes it takes all your attention to do this,but gets easier with practice. This is my experience from 45 accident free years commercial driving.