Heathcliff Characterization

It seems in the first few chapters that Heathcliff comes off as very abrupt. He has no care for the comfort of others, but seems completely focused on himself, specifically his past. The character that we see when his younger self is introduced in the diary seems to have a completely different personality. This would lead one to believe that something obviously happened in the intervening time that changed Heathcliff in a drastic way. From his reaction to the story by Longwood of Catherine's ghost, it seems to be linked to her. Her marriage to a man other than Heathcliff may have been what ruined him. His love for her could be something that tears at his heart and prevents him from connecting with others, perhpas showing his awkward social actions.