I understand that.
A loud, annoyed way of saying you’re too dumb to get what they’re saying and you’re mad they’re smarter than you.
'I understand that,' he shouted, while throwing a tantrum about not getting the joke.
'I understand that,' she said, even though she had no idea what was going on.
'I understand that,' he said, as if he were the teacher and she was the kid who failed math.