Sometimes ‘poor’ is used instead of ‘sad’. Even the most confirmed of pessimists can’t be miserable all the time. We can’t look for ever on the gloomy side of things.
Mrs Stevens looked up from the letter she had been reading at the breakfast table.
‘It’s from Mother,’ she said to her husband. ‘She can’t come and stay with us after all.’
‘It’s a sad heart, ‘ said Mr Stevens from behind his paper, ‘that never rejoices.’