Giovanni's Room Memory and the Past Quotes

How we cite our quotes: Citations follow this format: (Part.Chapter.Paragraph)

Quote #10

They pull him to the door of his cell, the corridor stretches before him like the graveyard of his past, the prison spins around him. (2.5.138)

Here, as David imagines Giovanni going to his death, he refers to "the graveyard of his past." Why might one's past memories seem like graves? Why might one's memories feel particularly like a graveyard as one is headed to one's death? Is David talking about the graveyard of Giovanni's past or the graveyard of his own?