You've got to drop it. Anger and fear are two emotions that focus the mind. A bad thing on a motorcycle because when you are really angry you lose peripheral vision and you target fixate on the object you need to kill or run away from. You also stop breathing long enough to affect the way circulation works, a big chunk of your body goes into anerobic respiration as your aerobic capacity gets overwhelmed by your adrenalin fuelled large muscle groups. If the event doesn't get you, the aftermath can because for a time after an event like that you are running at less than optimal.
Fear or anger also should indicate to a motorcyclist that they aren't expending enough energy on situational awareness. Riding, even in town should be a Zen affair. Negative energy is a lot more lethal on a bike.
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