You might think that the son of the world’s richest investor would be partying it up in some tropical locale while squandering the family fortune. But as it turns out, that’s not how Warren Buffett raised his children to behave. His son, musician Peter Buffett, is the author of the new book, “Life is What You Make It: Finding Your Own Path to Fulfillment,” detailing how he avoided becoming just another spoiled child with a very rich parent. Buffett has famously given away most of his billions to charity instead of his children, often lamenting the “silver dagger in...