What does it take for Toad to get puffed up and conceited?

The bargewoman greets Toad, who then cons her into giving him a road to Toad Hall. In exchange, he promises to wash her clothing while they float.

Thinking the job must be easy, he scrubs the fabric for a half-hour, to no avail. He really tries to show off. Finally, the woman cannot hold her laughter, and calls him out. She never believed he was actually a washerwoman. Humiliated and angry, he accosts the bargewoman until she throws him into the river.