Negative emotions like fear are not pleasant to feel, but they still play an important role in our life. Fear, for instance, indicates that there is a threat or danger to us. When walking alone on a dark street at night, a feeling of fear may indicate a threat to our safety. This fear activates the fight-or-flight response in the body, which then equips us to tackle the situation at hand. It also reminds us to look around and stay vigilant, thus keeping ourselves protected from danger.