On learning from envy see de Botton 2013, p. 179.
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There is another source of interesting learning that we often neglect.
We often view envy as a bad feeling.
But it can hold some critical pieces of information of what you deeply wish. All these pieces of information are like pieces of a jigsaw puzzle that you'll be able to assemble to draw a map of your future, little by little.
Thus, you can transform this 'bad feeling' into positive and growth-oriented outcome.