Ben Carson is having a wild week. Yesterday, Buzzfeed News uncovered footage of a late-'90s commencement address the surgeon-turned-GOP presidential candidate gave to Andrews University, and in it he lays out a curious historical “theory.”“My own personal theory is that Joseph built the pyramids to store grain,” Carson says in the video, taken in 1998.Joseph is a figure from the Old Testament who is sold into slavery and becomes a valued adviser to the Egyptian pharaoh. In the Bible, Joseph has a vision in a dream of coming years of famine, which allows Egypt to store grain and survive.In the video, Carson goes on on to say that the structure of the pyramids supports his claims. “When you look at the way that the pyramids are made, with many chambers that are hermetically sealed, they’d have to be that way for various reasons.”