You become

a displacement figure for the things in life that cause him
stress. It's only because we take these incidents personally
that we find ourselves being drawn into contentious
situations. If you think about it, that's probably why you find
yourself getting angry with people (especially those closest
to you), over little or nothing -you are also displacing your
unutilised aggression.
The combination of our confrontational society and
increasing amounts of neurological stressors means that we
are bound to develop pent-up aggression. Stores of stress
hormones sit waiting to be released by our behaviour,
awaiting the right trigger to let them go off with a bang. That
trigger might be a minor traffic incident, it may be some
lemon staring at you across the bar, or something as simple
as one of your children spilling juice on the carpet. Once
triggered, the pent-up aggression explodes in an
uncontrolled manner that can change the course of your life,
for the worse, forever.