1. Naming things 2. Cache invalidation 3. off-by-one errors
> The next time you sit down to an empty design doc and don’t know where to start, be kind to yourself. You’re solving a hard problem.
This supposed hard problem in computing has always been with us, in real life. Which he admits multiple times, e.g.:
> Yet Victorian-era gentlemen might have pondered the same questions while sorting letters as we do while sorting virtual paper.
He appears to claim that the sole organizing principle in real life is the hierarchy, but, of course, that computers and ideas are different:
> Hierarchies are so natural to us that they ... [work] for physical objects that can be in only one place at a time. Ideas and information, however, resist taxonomies. They form intricate webs that penetrate rigid boundaries.
This distinction of physical vs. virtual requirements doesn't hold up under any sort of rigorous analysis. As he admits, hierarchies are not always ideal in physical space -- do we organize parts and supplies separate from tools, or place them next to their probable job sites?
And of course, the "in only one place at a time" is certainly true for any given group of atoms, but we have become adept at making fungible copies of atoms for many things. I might have drywall screws or 33 ohm resistors in multiple cached locations, and I have soldering irons and screwdrivers and pliers on more than one workbench.
One thing that is true is that we can usually add non-hierarchical groupings to information more easily than we can to groupings of atoms.
Another thing that is true is that we already often do so whenever the convenience outweighs the various costs.
And the third thing that is true is that this, also, is not much different than the physical world, where we routinely both break our hierarchies and create copies of things when needed.