I love the Hahn-Banach theorem. I love it the way I love Casablanca and the Fontana di Trevi. It is something not so much to be read as fondled.
Thus begins the abstract to the eulogy "On the Hahn-Banach Theorem" by Lawrence Narici.
There's not much I can add to that. Have you ever felt this way about a theorem?
(I have a virulent dislike of analysis but I'm going to see if this paper can convert me.)