Reminding her of his past failings does not change how she currently feels. And will not affect her in any positive way that would soothe her about her failings. He took a more straightforward and positive approach telling her that she doesn't need to be in any rush to get her license. And he mentioned how he would miss practice driving with her. This approach made her feel less afraid of failure and made her much less nervous to drive on the road and practice driving.
