Mr. Brown said to me "Make good use of your time. You wont get such an opportunity again."

Mr. Brown offered me such an opportunity so that I could make good use of my time.

Mr Brown advised me to make good use of my time as I wouldn't get such an opportunity again.

Mr. Brown ordered me to make good use of my time, said that I wouldn't get such an opportunity again.

Mr. Brown let me make use of my time, knowing that I wouldn't get such an opportunity again.