I'm paranoid about stupid shit, like about bugs being in my bathroom, or about whether the milk has gone bad or not.
My girlfriend, on the other hand, is paranoid to the extreme. She makes life decisions, sometimes, based on 'how would this benefit/hurt me when the world ends?' For example, she's a transgender and will not get a sex change because if the world ended, her reliance on testosterone shots would inhibit her ability to survive. Also, she's quite paranoid about everything being fake, or computer generated, or not real. She told me once (when her paranoia was really bad) that she could only love me to a certain extent because she couldn't be positively sure that I was real.