I was reading a book on writing dissertations. I do this from time to time, in hopes that I might learn something new that will be helpful. This particular book had sections that I thought were poorly written, but it also had sections that I thought had good material (though mostly I thought it was good because it agreed with things I already believed; I was hoping for new ideas).
I was talking with a writer about feedback I had given, and about getting feedback from her professors, and emphasizing the importance of working on the feedback that makes the most sense, and carefully testing the things that seem wrong.
In both cases, of course, the main principle is that you take what you need and leave the rest. You don't have to throw the baby out with the bathwater. And you don't have to keep the bathwater. Whether you are working with sources, or working with feedback, or working with an old draft, it's worthwhile to keep in mind that things are not monolithic. Ideas, especially, are not monolithic. People and their opinions are most definitely not monolithic.
We can exercise selectivity in our work. We can look at the material we are working with and examine which aspects will work and which will not.
This seems to me a good exercise in learning both to find value in what is difficult, and to be able to look critically at that which is easy.
I was thinking in terms of selectively using ideas or pieces from a book when I wrote the title, but it is part of a line from a song by The Band. My initial thought about it as I started writing was that it was about not being greedy, and I twisted it, initially into my thoughts about not feeling it necessary to take things as a whole. But if we focus on the word need, then we have what is essentially a profound personal lesson: we should be striving to take those things that serve us in the most direct and necessary way, and leave other things.