Were those 249 years produced in a vacuum? Or did they stand on 1500 years of mathematics and trial-and- error? As a quick example, think of a high-end digital photographic camera; you can certainly highlight the major tech advancements that make it high end, but do you know how the screws were produced? Where the grease used on the gears cone from? How long did it take to get to the state-of-the-art optics? How can you even get composite materials to perform heavy-duty cycles?

Those 249 years of tech were based on the previous 249 years of tech, and so on and so on. That is how it works. Nothing you have "today" comes from a vacuum.