Delusional

Delusional:

de¦lu|sion¦al

ADJECTIVE
characterized by or holding idiosyncratic beliefs or impressions that are contradicted by reality or rational argument:

"All politicians are delusional"

One thinks nothing's changed.
One thinks he's won.
One thinks she didn't lose anything.
One thinks he's a northerner from up north, don't you know.

Only one of them is right!