Today's mailbag is overstuffed with your excellent contributions! We talk about how to keep cool in the face of big losers, relay a life-hack to make you happy, debut a new investing term, and even leave you with a tune worth whistling. All this and more in the March mailbag!

This week we look at Malcolm Gladwell’s 2009 New Yorker article, “How David Beats Goliath” and extract three inspiring investing lessons. Gladwell spells out the hidden advantages of being the “underdog” in a way well-suited to our Rule Breaker investing style.

Thanks to Audible for supporting our podcast. Listen to Audible's new original series: Ponzi Supernova. Details at audible.com/ponzi. Audible and Amazon Prime members listen free.

Often the best way to improve our investing is to improve our thinking. And to improve our thinking, it’s often helpful to reach outside of the disciplines of investing and business. Today we delve into the teachings of education reformer, Deborah Meier, and the “5 Habits of Mind” that she believes should be taught to all 21st Century students. Perhaps these habits should be taught to 21st Century investors as well!

From the earliest days of The Motley Fool, our mission has been to "Educate, Amuse & Enrich." Today we double-down on the "Educate" with an exploration of some commonly used financial terms. Guest analysts Andrew Fredrickson, Abi Malin, Aaron Bush, and Jim Mueller join David to define and discuss net profit margin, cash flow vs. net income, dividend yield, burn rate, and spiffy-pop!

Today we present a third installment of tips, tricks and lifehacks—to help you be a better you. Find a hidden superpower in your Kindle app, improve your investing while learning to draw, achieve your goals by ignoring them, and much more! Do you have a favorite mental tip or trick? Share it with us on Twitter @RBIPodcast.