We are meant to understand how silly Mrs Bennet is. On the one hand she says, "When they get to our age I dare say they will not think about officers any more than we do," but in the very next line she contradicts herself: "I remember the time when I liked a red coat myself very well -- and, indeed, so I do still at my heart." She is as silly as she was when she was a girl.

Mr Bennet, on the other hand, is not being silly. He knows their sentiments rarely coincide at all, but he is sniping at her in an understated manner which she does not at all comprehend. A wonderful instance of this is in the first chapter, where he suggests Mrs Bennet should send the girls to Bingley alone, "for as you are as handsome as any of them, Mr. Bingley might like you the best of the party." He can't possibly be serious here, but she answers as if he was: "When a woman has five grown-up daughters she ought to give over thinking of her own beauty." His reply is a 'subtle' jibe which goes completely over her head: ""In such cases a woman has not often much beauty to think of." Mr Bennet takes pleasure in sporting with his wife, knowing she will not understand him.