Gold is buried in sand, which is the least valuable, but the gold obtained after scouring the yellow sand is priceless, so the emergence of gold needs more efforts.
Success is enviable, but the usual efforts are as boring as sand and seem worthless, and there seems to be no trace of success.
But without usual efforts, success will become an elusive thing.
Therefore, when writing, we should emphasize that success is hard-won, and cherish efforts like sand.