“stay the course”别理解成“待在课堂上”，真实含义是坚持到底。

【例句】
Despite an early setback in the first half, the home team stayed the course and managed to earn a draw.
尽管遭遇了上半场的挫败，主队仍然坚持到底，设法获得一场平局。

The training takes years and a great deal of work, but if you stay the course, the rewards are fantastic.
培训会花很多年的时间和大量的工作，但是如果你坚持到底，回报也是非常好的。