- Product Market Fit - find that before continuing to perfect the product. - Market size and especially addressable market size. We learnt it the hard way with children's apps. - Tech is a tool. Unless you are doing groundbreaking research, dont be in awe of the tools (tech), nor let it go crazy expensive. - One needs a deep reserve of patience and strength, you will get challenged in all dimensions. - Sometimes you can do everything right, and still fail.