I was primarily making an argument the other way around: I said that understanding the subcomponents (i.e. the letters) did not guarantee understanding of the whole (i.e. the sentence), while you're giving an example in which someone builds a whole, presumably by understanding and replicating the connections of major components, but does not understand the parts. More analogous to my point would be attempting to understand the workings of a clock by examining each gear.
Also, I don't know that your thought experiment holds water. I can certainly conceive of a universe in which a person never makes the logical leap from holding a clock and parts—or even having a thorough understanding of the workings of the subcomponents of a clock—to building their own. The pre-Columbian New World civilizations, for example, had all the resources to build wheeled vehicles, and certainly understood the principle behind them enough to build wheeled toys or use rolling logs to transport large objects, and the Inca Empire even had a sprawling complex of roads—but never in their long history did the notion of a wheeled cart occur to any of them. Which is to say: the search space of ideas is vast, and one can't reasonably be expected to exhaust them all even with help.
Also, I don't know that your thought experiment holds water. I can certainly conceive of a universe in which a person never makes the logical leap from holding a clock and parts—or even having a thorough understanding of the workings of the subcomponents of a clock—to building their own. The pre-Columbian New World civilizations, for example, had all the resources to build wheeled vehicles, and certainly understood the principle behind them enough to build wheeled toys or use rolling logs to transport large objects, and the Inca Empire even had a sprawling complex of roads—but never in their long history did the notion of a wheeled cart occur to any of them. Which is to say: the search space of ideas is vast, and one can't reasonably be expected to exhaust them all even with help.