If you met your future self
... and they turn out to be whatever you would consider to be the ideological opposite of who you are now (i.e. if you're a libertarian they'll be a mega-authoritarian communist, if you're a communist then they'll be the fucking monopoly man or something), how would you feel?
Would you trust them? Would you then think that their ideology must be valid, or would you believe your future self to be wrong?
Also keep in mind this doesn't have to be purely political. Whatever you strongly believe in, political or otherwise, they're the opposite.
EDIT: Your future self is also more physically attractive than you