A drop of rain falls on a bear leaning up against a cross stuck into a mound. The drop wakes the bear up and he rolls down off the mound. After the bear rights himself, he assumes that the cross pushed him off the mound so he charges into the cross atop the mound and knocks it over.
Once the bear fully wakes up he realizes that he just rolled down the mound on his own and the cross was not to blame. What a fool (ふ) this bear was. He knows it too. The bear feels pretty foolish.