1) The author shares lessons learned from failing in their first startup, noting that an initial unsuccessful startup without major damage is valuable experience.
2) When starting a new business idea, it's important to turn off emotions and ask tough questions to critically evaluate the idea's uniqueness, market fit, and viability rather than just seeing if people like the idea.
3) Founders should test business models conservatively by dividing expected sales and revenues, prepare for worst-case scenarios, and focus on businesses they understand well to have the best chance of success in the first year.