Usually we're not even aware of it. Our mind just takes over and reaction sets in. We become victims to our own past. You have the ability to choose differently and choice is the key. Choice is about responsiveness instead of reactiveness.
Reaction is automatic and without thought.
Response is intentional. Response is personal control over your thoughts, choices and actions. First you need awareness and then comes choice. Take a good look at your life through new eyes. After awareness comes choice.