Ex-girlfriend as part of his history

Every time he mentions about his Ex-girlfriend it gives me a headache. However, his constant chatter might actually be an attempt to get closer to me, not push me away. Maybe it’s his way in order to make me understand and know him better. He may think that by divulging about his history, gives me full scoop on where he’s been and how it made him who he is today. I just love to listen when he gives facts about his past, not a sense of lingering attachment that just won’t go away. Just putting my ego aside and reminding myself that these stories have nothing to do with me and our relationship and accept his stories as part of his history before me.