My favorite example is the Antikythera mechanism. It is quite clear that this had not been a one-of-a-kind, but that there must have been (many) predecessors of this technology to arrive at the kind of workmanship and layout that doesn't show any marks of hesitation or corrections as in the sole example, we know of. And that we know of this example at all, is just by sheer luck.

Generally, we only know of landmark size applications of historical technology, which tend to be rare.

It probably wasn't as common as the slide rule was in the 50's but I'm pretty sure there were more of these and some predecessors as well. The chance that we have found the only example that ever existed for something so useful seems slim.

It's probably the case that foundations get invented pretty darn quick in a civilization that builds primarily with wood. Wood rots too fast in environments where (a) trees grow and (b) wood is in contact with the ground.

Midden heaps can also close the gap.