I understand that.
A Cajun from Louisiana saying they're too dumb to get what's going on and they're just confused and annoyed about it.
'I understand that,' he said, even though he had no idea what the other person was talking about.
'I understand that,' she said, while trying to figure out why the chicken had no legs.
'I understand that,' he said, even though the person was speaking in English and he thought it was French.