Egyptian priests told Greek historian Herodotus, that the pyramids had always been there.
No, as a matter of fact, they told him nothing of the kind. He discusses various pyramids a bunch of times, and not once does anything of that kind every come up. He talks about where some of the stone was quarried for the "Memphis pyramids" (Giza and Abu Roash), describes a couple of Middle Kingdom pyramids that were still in good shape in his time (they were built of mud brick, and didn't hold up as well as the masonry pyramids), etc.
I'll do more research and get back to you on that.
Meanwhile, the physical evidence strongly suggests that the pyramids and other megalithic structures in Egypt, could not have been built by the dynastic Egyptians.
I understand that many people are wedded to the traditional mainstream narrative of Egypt's monuments, but those views have become unsupportable, in light of closer observation and analysis over the last few decades.