David knew about that. He knew that he would bear the consequences of his sin throughout his life. And those consequences can be awful. One moment of thoughtlessness can cause a person to weep for years. What was so cheaply bought, so cheaply given-the payment for that can come in later life in terms of years.
Sin is a monster.
Sin is not a cuddly plaything. Sin is not a cheap little enjoyment that comes with no cost. The scars of this monster sin will be with you for life. It is evil in terms of this life. Very often the consequences for those sins in terms of this life cannot be undone.