This mirror probably saved me a trip to the hospital this morning.  I was nearly rear ended by a car when I stopped at a traffic light.  The only reason I wasn't hit, was because my obsession with always checking behind me when I stop or slow down sharply on a motorcycle.  I saw the car approaching fast, heard tires skid, and I slipped the clutch and popped the throttle and moved out of the way.  It would have been close

.  The driver was either pre occupied, didn't see the light change, or was following too close.  That's another reason to be careful, motorcycles compared to cars can stop on a dime.  In hindsight, I probably could have ran the yellow light as it turned red, but that's not ideal either.

So here's what you need to do while riding a motorycle:  always check behind you.  So often riding a motorcycle, we are only concerned with the dangers ahead, not what is behind us.  Every time you make a lane change, stop to turn, or come up to a stop sign or light, look behind you.