Some people refer to the slight edge - the little decisions that we make is all that matters as every action that is made is compounded over time.
Others often are familiar with the snowball effect - start small and build upon what you have.
More recently, on an Indie Hackers podcast (about 30 minutes in), I heard the term exit velocity - which is how much professional and entrepreneurial momentum you have when starting you new project or business. Typically when you are new to the world of business it is hard to gain any kind of traction as you most likely haven't had the chance to build up your contacts, relationships, knowledge, experience, capital, investment and so forth.
The slight edge, snowball effect and exit velocity are all important mental models to bear in mind when building your business. The more I see and learn how others are building successful business, the more I see these models have been crucial to their success.
Indie hackers newer to the game can quite easily miss this. They will look in from the outside, believe that they understand why said person has succeeded, but really the underlying factors are down to a million little things that have most likely happened over at least a 1000 days.