I think it was at the point that the little boy was being driven in reckless fashion by his mother along a cliffside road overlooking the sea, and the sea was roiling with hundred-foot waves that were really gigantic koi but were also waves, and the waves were moving straight up and down like elevators half-sentient elevators, and running/riding on top of the waves was the little goldfish who (having tasted a drop of blood from the little boy's thumb when she was much smaller and living in the bucket that the little boy had kept her in after saving her from the glass jar she had swum into and gotten stuck in) had now grown human-sized and had sprouted chicken legs and was laughing, laughing, laughing, and oh, yeah, also those giant fish-waves she was running on were the evolved version of the tiny little goldfish who were once tiny versions of herself . . .
Yes, it was around this point in time that I sat back, smiled, and thought, "Hayao Miyazaki, you insane, magnificent, insane, insane bastard, I love you."
Ponyo is minor Miyazaki compared to Spirited Away or Howl's Moving Castle -- its ecological message is somewhat muddled and it never really feels like there is much at stake (when one character starts blathering about the impending end of the world, neither the other characters nor the audience pays much attention -- but it still bears the stamp of the master. Crazy double-reverse pretzel logic presented in such a matter-of-fact manner that you accept it with childlike wonder, a sense that anything is possible, coupled with a humanistic sense of grace for even the most off-putting of characters, an absolute refusal to present any character as an antagonist. I have to say, there's nobody else making movies like this. I'm not sure how they could, or if they'd even want to try. Just trance out until the first paragraph of this post makes sense.
Image from http://themoviekit.com