The correct answer to this open question is the following.
Unfortunately, you did not specify to what time you are referring to.
That is why we are going to answer in general terms.
What could have happened if you were impulsive during a moment of conflict or during a tense moment is that you can end up creating the worse scenario, instead of resolving the issue.
When you act impulsively, you get angry. The angrier you get, the most difficult it to control your actions. If you cannot control your actions, you do not think, you react. When you react, most of the time the result is aggression.
When acting impulsively, you are prone to get into fights. You can hurt other people or you can get hurt.
And later, after the moment passed, you are regretful. You feel sorry. And of course, you have to assume the consequences of your actions.