system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why don't we already know everything that's inside the pyramids?

In response to the news about temperature scans revealing "anomalies" in the pyramids that may be additional burial chambers etc. - why don't we already know exactly what's in there?  These are some of the most famous buildings in the world, they are not new discoveries and I don't understand why they haven't been explored from top to bottom by now.
gpt
Two people ahve answered that the pyramids are "incredibly complex"- they aren't- they're giant piles of rocks, with narrow shafts and a few small rooms inside.  We know about those because the shafts reach the surface.  There may be other rooms, but it would require tunneling through tons of rock to access them, because there are no doors or hallways to these rooms, and millions of tons of rock on top of them.