I fell into the magic of biochemistry in my teens, when I read an article describing how our cell membranes hold together and self-heal in a stunningly simple manner. Oils repel water and will clump together-- they are un-ionized and are called hydrophobic. Their opposite--hydrophilic elements (salts, sugars, etc.) will dissolve in water. But cells both clump together in droplets like oil, and contain water on the inside. They achieve this trick by having long, complex molecules with hydrophilic heads and water-hating tails. The tails clump together in the middle,and the heads fan out, forming two layers-- one external, one internal. Diagram.
There are many proteins that serve as pores for our cell, but most of our cell membrane is as simple as plastic balls with rope tails floating on a swimming pool. Dive in, and the plastic balls will part and swing back together. There is nothing to tear, because nothing is fused.
And this simple self-assembly principle is how our proteins grow from linear DNA blueprints; once the peptide (protein parts) are assembled, they will almost immediately fold themselves, as hydrophobic amino acids attract each other with hydrogen bridges, while hydrophilic amino acids try to dissolve in the surrounding fluid. But this takes many stages, and sometimes other proteins will cut away bits, or create stiffer bridges between different parts, which allows the protein to move to a new level of folding.
Many complex proteins actually have parts made up from separate genes; they are produced with excess tags to prevent folding until the parts are unified. Then the cutting happens, and the peptides fold into the completed protein, elements fusing or getting built on. When things go wrong and things are stablized too early or not early enough, we can wind up with deformed proteins that then must be broken down and recycled.
If we think about this analogy, we suddenly see that revision also has many stages; Revision often must cut what seemed good and necessary in the first draft. Very different pieces can be cut and put together, which suddenly gives new structure. Connections must be made between different parts, and that can suddenly cause the story to fold into new directions. And no matter what, sometimes the wastebasket and starting over again is simply the best solution by far.