In David Perkin's book Making Learning Whole (2009) he has a chapter called "Working on the Hard Parts" in which he stresses the importance of mastering difficult skills and knowledge in order to get to the next level of performance. One of the exercises he has his students (teachers-in-training) do is to devise a Theory of Difficulty (TOD) for a given domain of skill/knowledge. The TOD is supposed to help these teachers-in-training to come up with a better curriculum for learning that skill/knowledge.

It may be useful to think about the TOD associated with successfully starting a particular line of business.

Imagine that instead of you starting your business, you have to teach someone else about how to start your business. Your TOD might start with these two questions:

1. What makes starting my particular line of business difficult?
2. What would the person have to learn in order to overcome those difficulties and be successful?

If I am starting a bike rental business the difficulties I would face in doing so are different than if I am starting a software development company. There are different things I have to be good at and master. A TOD for starting a business can't really be specified in abstract terms. David Perkins is critical of TODs that are overly general and often gives his students this feedback:

Please think about this some more and give us a theory of difficulty that is more specific to your topic. Give us one that doesn't sound like something that could be said for a hundred other topics. There are alot of topics that are complicated or commonly boring or initially unfamiliar or packed with points to remember. Please get specific! You see, theories of difficulty afford much more leverage if they target the particular learning challenges for that particular thing. ~p. 102

It is arguably much easier to come up with a TOD when there is established knowledge for the domain. In the case of starting up a particular line of business in a particular place, there may be no rulebook unless you are starting a franchise that provides ample guidance on these matters. Your TOD is subject to revision as you learn more about how to succeed in your particular line of business. You may learn, for example, that alot of your bike rental clients are coming from tourist accommodation owners advising tourists on what they can do. Now your marketing approach needs to change to target these accommodation owners. The particulars of what makes marketing your business challenging has changed.

When an entrepreneur starts a business they probably already have an implicit TOD about the challenges of starting that business. Perhaps it would help to be more explicit so that assumptions about where the difficulties lie are clearer and more subject to testing, revision, and hopefully mastery.