People take a lot of approaches to things. Some get the idea to build something and just dive in. Others read and study the project, then start. Others look for someone to show them how to do it. Some look for someone else to do it. Others just have the idea but never do anything about it all; except maybe talk about it.
I think life is one big project. We should be building our lives the way we want them to be. Some people just dive in and go with it. Others look for instruction and guidance. Some look for someone else to do it. Others talk about living but don't quite seem to be going anywhere.
There are plenty of instruction manuals. The challenge is that it's such a long project with so many variables that no one set of instructions covers everything. I've yet to meet someone who isn't improvising. The compass might be pointing a specific direction but everyone runs into a swamp or two along the way.
Maybe there aren't clear and concise instructions because the point of the project is to learn to improvise.