The thing about castiel's confession -- IF you take it romantically -- is that HE DIDN'T EXPECT DEAN TO SAY IT BACK. HE WAS COUNTING ON LACK OF RECIPROCATION. THAT'S WHY HE SAID "SOMETHING [HE CAN'T] HAVE". THAT'S WHY HE HAD TO COME TO THE REALIZATION THAT "THE HAPPINESS IS IN JUST SAYING IT".
JUST SAYING IT
HE KNEW DEAN LOVES SAM MOST OF ALL. HE'S ALWAYS KNOWN.
It's kinda the thesis statement of the show.












