I couldn't have been more mistaken.I mastered the skills of that beginning level position and I was given the opportunity to move up through the company into different positions.
我没有可能错得更离谱了.我掌握了所有的基本工作技巧并且有一个升任公司其他职位机会.
这里应该只是节选,后面的大致意思猜测是 他没有把握这次机会,现在非常后悔