Sooner or later we all have to deal with stress in our lives. At work, in our relationships, due to persistent gloomy thoughts or because our bodies do not function the way we would like.
Perhaps because of too many "have to do's", we experience restlessness, anxiety, insomnia, heart palpitations and all types of pain. Many people become sick from stress. You even read about teenagers with a burnout!
There is not much that can be done about the primary causes of stress, they are part of life. Everything is perishable. Relationships are on the rocks and our dream job we had imagined turns out to be something different. We cannot choose our parents or our genes. As we get old(er) we will experience sickness and eventually we will die.
In short: we can never completely eliminate annoying events, pain, sadness or negative thoughts. What is possible is to learn how to relate to it differently. What we often do is push it away, deny it, hide it, ignore it or make ourselves so busy (i.e. by helping others) that we simply don't have time to reflect on our own pain or problems.
You have probably already noticed that that does not work anymore. With mindfulness exercises you can learn how to deal with it differently. Changing your automatic response to it, so that, for example, you are less likely to get pushed over the edge or become angry.
By being able to be present with a friendly open attitude to experiences of stress instead of pushing them away, you start taking better care of yourself, you become beter and faster at understanding what you really need.