Although I am not a grandparent yet, please allow me to tell you a story as an elder brother at least:
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Once there was a young wolf who wanted to be the leader of the pack but was simply not big enough to challenge the current leader. So he decided to go and meet with the lion to learn something useful which could help him do that. The lion agreed to take him on the next hunt to teach him new skills.
So both the lion and the young wolf crept up to a deer in the bush. The lion asked the wolf,"Is my tail erect?" The wolf said, "Yes, Sir!". The lion asked," Are my eyes red?" "Yes". The lion asked "Are my ears up?", "Yes" came the reply. The lion said, "Now I am ready!" and with a mighty leap sprang upon the deer and captured him.
After learning this useful lesson, the young wolf went back to his pack and gathered them all around him and said, "I have come to be your leader, because I have been taught by the lion himself. Follow me and you will never want for fresh meat!" The wise leader of the pack said, "Well, that is good. Why don't you demonstrate your skills, and if you can hunt as well as you say you do, then I will step aside gladly."
The young wolf boasted, "Show me the animal to be hunted!" and the leader pointed out a water buffalo in the the savannah. Upon seeing the mighty animal he was supposed to bring down, the young wolf's heart leapt into his throat, but he had the whole tribe looking on, so he trembingly stalked the water buffalo, and then jumped upon it.
Of course, the buffalo gave him one mighty kick, flinging the poor wolf far into the bush, bruised and broken. All the pack laughed at him and went away, except a few friends, who came to look after their friend. One asked him, "Whay happened? I thought you were trained by the best!". The young wolf meekly said, "I would have killed the buffalo, except that my tail was not erect, my eyes were not red, and my ears were not up."
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First moral of the story: First, get ready.
Second moral of the story: Even after you get ready, don't be over ambitious.