第二个教训是不要不动脑筋地急于抓住蝇头小利。

The second was not to rush unthinkingly to grab a small profit.

管理者通常会认为，某人身居要职，收入不菲，为什么会甘愿为了蝇头小利而冒身败名裂的风险？

In the eye of managerial personnel, well-paid senior staff holding important post will not be likely to ruin his fortune and honor at the risk of petty profits.

她的意思是她在为数额很小的钱而工作（peanuts，俚语，极小之物，极小数额，蝇头小利）。

She means she is working for a small amount of money.