The Yesod HaAvodah (vol.2, 6) wrote in a letter, “Years ago, during a war, the general received a letter saying that the enemy had broken through their military strongholds. The general became very down, and he told his wife the news.
“She replied, ‘I also just received a letter. It came just this minute. It tells of a greater loss than what you told me.’
‘Really! What does it say?’
‘It says that in addition to losing that fort, you lost your morale (your מוהט) and that is the greatest loss.”