Stalkers display an obsessive personality.
They are not just interested in, but totally obsessed with the person they are pursuing. Their every waking thought centers on the victim, and every plan the stalker has for the future involves the victim. Ask yourself this. Is the person totally involved in and completely overwhelmed with pursuing someone who has no and never will have any interest in him or her?
Along with obsessive thinking, they also display other psychological or personality problems and disorders. They may suffer from erotomania, paranoia, schizophrenia, and delusional thinking. According to Professor R. Meloy, “these stalkers have rigid personalities and maladaptive styles. These disorders in themselves are very stable and not treatable.” There are drugs to treat certain specific mental disorders, but stalkers, when given the choice, seldom continue with their medication or treatment.
BTW, you're the one with the clear agenda. Not me.