Peter isn't entirely mentally healthy and was previously a stalker. He had a lover who died in an accident, leaving him with his only daughter. This is the only thing keeping Peter alive, as he adores her and treasures her beyond measure. He has a somewhat warped sense of care, sometimes bordering on overprotectiveness. Letting go of even an adult child would be practically impossible for him, he strives to be the perfect parent, despite the control and limited social life.