The master is clearly giving useless advice, but it's phrased as a koan so people are assuming that they're just misunderstanding it and that there's deeper meaning they're missing. The student is reasonably stating their problem for context, and then asking the master what to do about it. The master is responding with a lecture to not waste time "elaborating your misery" (which they didn't do) and telling the student to figure out what to do about it (which is exactly what the student asked in the first place).
"the student was enlightened" = the student thought "master is worse than useless when it comes to giving advice, I shall not bother him with further questions"