secret identity
when ur a super hero, or an evil villain and u must pretend u are part of the real world for some odd reason.. i dunno maybe so we as people can relate to part of the story line. and it's exciting to watch them almost get figured out.
i personally don't understand the reason for secret identities besides making a story exciting. in reality if this person was a super hero, why would he/she have to pretend for a while he/she was a regular person?