They don't worry about that. If God would take care of birds and flowers, how much more would the Lord God take care of you, for you are the children of God. So, don't worry about what happened or what's coming. Don't worry about life at all. Just live in the fullness of each day, understanding that today is the only day that you can do anything about.
Today is the day to work on life.
But actually, every day of our life, every stage of our life, has both its joys and its worries. There are some wonderful things and some problems about every stage of life, so live in the midst of that day-tight compartment and make the most of each day. So many of us spend far, far too much of our time and energy riding this conveyor looking backward, remembering how great it used to be back there instead of enjoying the scenery of where we are. If we could just go back to what used to be, how marvelous it would be. But of course, we can't.