We’ve had this long-held philosophy at Amazon about two-way and one-way door decisions. A two-way door decision is one where if you get the decision wrong, you can walk back through that door, revert to where you were, and there are few (if any) ramifications. You can make these decisions quickly and locally. A one-way door decision is one where it’s quite difficult (if not impossible) to walk back through that door if you get the decision wrong, so these decisions are made more methodically. But, both of these constructs assume the door is unlocked. A lot of invention is about trying to open doors that have historically seemed bolted shut. And, over the past 30 years, we’ve found one of the most important keys to unlock these doors has been a simple question: “Why?”