Why is obsessive love only weird if you're not obsessively loved back?

I couldn't be truly in love with somebody who doesn't love me back, cause that would fizzle the love on my end out. So with those people who seriously love someone, but then they don't respect the other person's wishes if they say they don't love em back, and they still stay madly in love anyway, that's when it turns creepy. The creepiness comes when one refuses to respect the other one's wishes.