Just so you know, absolutely none of that is true.
https://en.wikipedia.org/wiki/Pyramidion_of_Amenemhat_III
I don't know if the person who posted that is sincere or not, but plenty of people sincerely believe this sort of thing when it is posted on Facebook.
The actual mysteries are so interesting without making up stuff or bringing up the annunaki. Whoever built the original pyramids was smart as heck, knew the size of earth and probably spanned the globe yet there's like no record of what happened to them or their civilization. Then the ancient egyptians (that we actually know about) came along and were like imadethis.jpg. Source: some youtube videos.