Listen to everyone in your company and figure out ways to get them talking. The folks on the front lines—the ones who actually talk to the customer—are the only ones who really know what's going on out there. You'd better find out what they know.

解释：货卖完了才知道不足，是由于不懂得计量；事情结束了才知道有余，是由于不懂得调节。

解读：这是人生规划的关键三连问，盘点现有资源、明确目标，进而知晓需割舍的东西，合理规划人生走向，避免盲目奔忙。

数学是理性的音乐。