Being a vampire for him meant revenge. Revenge against life itself. Every time he took a life it was revenge. It was no wonder, then, that he appreciated nothing. The nuances of vampire existence weren't even available to him because he was focused with a maniacal vengeance upon the mortal life he'd left. Consumed with hatred, he looked back. Consumed with envy, nothing pleased him unless he could take it from others; and once having it, he grew cold and dissatisfied, not loving the thing for itself; and so he went after something else. Vengeance, blind and sterile and contemptible.