One of my first jobs was as a telemarketer for a telecom provider. It was basically cold-calling people all day, trying to sell them mobile contracts

I picked things up quickly and became the top-performing salesperson on the floor. In my first month, I made at least five sales a day, which was more than double what others sold.

People praised me big time. It also got to my head big time. By my fourth month, I got into a big slump. During one stretch, I didn’t sell anything for almost two weeks.