It is a great pleasure to tell how I served my apprenticeship as a businessman. But there seems to be a question preceding this: Why did I become a businessman? I am sure that I should never have selected a business career if I had been permitted to choose.

【翻译】很高兴告诉你我是如何做学徒经商的。但在此之前似乎有一个问题困扰我：为什么我要成为一名商人？我确信，加入我被允许选择自己职业的话，我就永远不会选择商业职业的。

preceding this：是现在分词短语，作定语修饰question。翻译时，可以按照介词before 理解和翻译。

动词 precede：“先于；在......之前”。