A kindergarten teacher told each child in the class to bring along a plastic bag containing a few potatoes. Each potato will be given a name of a person that the child hates, so the number of potatoes that a child will put in his/her plastic bag will depend on the number of people he/she hates.
So when the day came, every child brought some potatoes with the name of the people he/she hated. Some had 2 potatoes; some 3 while some up to 5 potatoes. The teacher then told the children to carry with them the potatoes in the plastic bag wherever they go (even to the toilet) for 1 week.
Days after days passed by, and the children started to complain due to the unpleasant smell let out by the rotten potatoes. Besides, those having 5 potatoes also had to carry heavier bags. After 1 week, the children were relieved because the game had finally ended.
The teacher asked: “How did you feel while carrying the potatoes with you for 1 week?” The children let out their frustrations and started complaining of the trouble that they had to go through having to carry the heavy and smelly potatoes wherever they go.
Then the teacher told them the hidden meaning behind the game. The teacher said: “This is exactly the situation when you carry your hatred for somebody inside your heart. The stench of hatred will contaminate your heart and you will carry it with you wherever you go. If you cannot tolerate the smell of rotten potatoes for just 1 week, can you imagine what it is like to have the stench of hatred in your heart for your lifetime!!!”
Srila Prabhupada explains:
The Srimad-Bhagavatam states a person must have the qualities of titiksa (tolerance) and karuna (compassion). In the character of Lord Jesus Christ we find both these qualities. He was so tolerant that even while he was being crucified, he didn’t condemn anyone. And he was so compassionate that he prayed to God to forgive the very persons who were trying to kill him. As Christ was being crucified he prayed, “Father, forgive them. They know not what they are doing.”
In the Krishna Consciousness Movement there is no question of enviousness, hatred, things like that. If ill-feeling is there, then stop it and all together chant Hare Krishna.
One should treat all living entities with tolerance, mercy, friendship and equality. By such behavior one satisfies the Supreme Personality of Godhead, and upon His satisfaction the devotee immediately becomes free from all material conditions.
REF. SB 4.11.14
"Art of Living stories" 