Those two things can coexist.

I have a festering interest in killers. Specifically, in serial killers.

While this may seem weird, creepy, or morbid (all words my mother likes to use), I think it is perfectly natural.

Some people like baseball. Some people like bird watching. I like building a vast knowledge on serial killers.

When ever I say that, people freak out. They give me this look that annoying little look, like they suddenly think I am mentally ill, and then they start talking to me in condescending voices, as if they were a therapist and it is the fifty's. Or a look of pure, horrified shock will stretch across there face, like they just  saw me sacrifice a lamb.

I am not going to start killing people. I am not mentally unstable.

Why is it so hard to understand that I am fine, and I like knowing about serial killers.

Those two things can coexist.