What do the last three sentences mean?
"yes,' Lanser said, 'I know. It's a thing I've talked about so much. You know,' he said, 'I might be a major-general if I hadn't talked about it so much. We trained our young men for victory and you've got to admit they're glorious in victory, but they don't quite know how to act in defeat. We told them they were brighter and braver than other young men. It was a kind of shock to them to find out that they aren't a bit braver or brighter than other young men.'
Loft said harshly, 'What do you mean by defeat/ We are not defeated?'
And Lanser looked coldly up at him for a long moment and did not speak, and finally Loft's eyes wavered , and he said, 'Sir.'
"thank you." said Lanser
"you don't demand it of the others, sir.'
'They don't think about it, so it isn't an insult. When you leave it out, it's insulting.'