He was not a loser as I had been led to believe. He tried the best he could, and when he realised that he would not get the Grapes, he knew it was time to give up. He commented on the sourness for good measure, to give himself the strength to stop trying.
One of the most definite signs of a loser is that he continues to run after the finishing line.
There are things like hardwork and persistence. Then there are things like crawling on all fours and begging and pleading and returning, even after you’ve been kicked out. The line between the two is very thin. It is where Dignity ends.
You do not run after the finishing line, it is foolishness and a waste of energy. What you do is find the next race and try to win. It is important to know when to stop and move on.
The Fox was dignified, he knew he would never get his hand on the Grapes. He accepted the fact and turned back. He did not keep trying until and after the grapes were eaten by birds or the vine had died. He knew when to stop. His was the honourable decision.
Who knows, he may have found better Grapes at the next juncture.