At the core of every startup is a model based on a set of assumptions of the way the world could operate towards furthering specific human endeavors. The goal of each startup is thus to systematically prove or disprove that the underlying assumptions hold true empirically, and the model itself viable and self sustaining at scale.
The discipline of the executor is to first sort the sets of hypothesis from most to least critical and thereafter consistently maintain focused deployment of resources to validating this list and nothing else.
It is important to note that patterns of recursion might be observed during the exercise where a hypothesis itself when acted upon yields its own subset of hypothesis that needs to be validated.
Startups are like an exercise in applied philosophy to satisfy the curiosity.