Why was it that Astinus seems like he is cold and unfeeling?

Astinus seems like he is cold and unfeeling because he must cut himself away from his emotions to stay sane. Through his records, he's been born and has died numerous times, and he's felt every emotion as though it were his own. He has committed the blackest deeds, murdered children, been both male and female, borne children, and his passion goes into his words.