In the middle of the writing process, challenges always arise. A melody won't sit right at first, or a rhyme won't seem to come.
When we remain attentive to whatever we've written so far--even if it's just a chord pattern or a few lines of lyric--we might discover that the solution is already there. When the most natural or "right" note is played, we are surprised that it was right in front of us all along.
This is true in nature and in other challenges we face in life. A solution is often readily available, easy to access and enjoyable to carry out. Often the way to find it is simply to relax with whatever good things we already have, and listen for more of the same.