I came across an old post from Sam Gerstenzang which summarises pretty well what I have learnt in four years of starting companies through Founders.
"Silicon Valley loves the mission-based startup and retroactively constructs a founder mythology. But big companies get started because someone takes the leap, she listens to encouragement, and ignores the haters until the company reaches product-market fit. That part is always the same."
It reminded me of a chapter in "Thinking, fast and slow", dedicated to entrepreneurs' innate, and illogical, optimism. It also reminded me of Indiana Jones and the last Crusade, when Indi is facing the second trial and has to take the "leap of faith" to reach the Graal. Imagine if he had simply fallen down, ending his quest, and the movie, in the most unglamorous way. Celebrating faith is easy when it turned out to be the right choice, yet any rational person should not have attempted that in the first place.
There are a couple of ways to overcome rationality and take the leap. The first one is to be blind to the challenge, either because we believe so much in ourselves or because we are naive and wholly unprepared. The other one is to trick our mind and push any true probability assessment to a later moment. This is Paul Graham's "questions", and it still the best trick I know to get started.
Each startup is a journey against sound thinking and probability. It begins with the irrational decision to attempt something that is doomed to fail and it continues through the delusion of persevering when any sane person would quit and do something better with their life. Until one day you make it, and it all becomes obvious.