Ainda não temos significados para "all-important lesson".
1That possible combination of hearty, youthful glee and true religion is the all-important lesson of this passage.
2He had been taught the all-important lesson that a hunter should not let his firearm remain empty.
3An ascent carried out later in the same summer led to a mishap, which taught the young aeronaut an all-important lesson.
4'Then you have learned an all-important lesson, which I trust will not be soon forgotten.'