Imagine you’re in traffic and somebody cuts you off, your initial reaction is to blow up, get angry and frustrated. You honk your horn longer than you ever have before because it was actually a close call.
Now you have a decision to make. Are you going to have a “good day” or a “bad day?” If you’re in control of your emotions, you can continue on with your day and remain positive. If not in control of your emotions, you let this encounter affect the rest of your day. Every interaction with you have with a person afterwards will be slightly affected. They’ll be slightly poisoned by the negativity that you bring to the interaction.
Controlling your emotions isn’t about changing your reactions to things, certain situations will likely still piss you off. The difference is that being in control of your emotions gives you the power to not let this event (that was out of your control) affect your future self.
“The most important of these skills, and power’s crucial foundation, is the ability to master your emotions.” -Robert Greene (pg.xix)