You were made to oversimplify, to find solutions, recognize patterns, attribute names and properties to things, situations and relations among objects and people. You need these notions to be able to think, but along the way of this noble purpose there is a parallel route that implicitly whispers there is a solution to all things and that, in elegance of existence, a same method should be applied to all things. This is not possible because the context of each new thing that happens or you encounter is never the same, it is highly mutable, subjective and elusive. Not even hard science can find a theory of everything – because there is none. Even strict verified rules have exceptions that can’t be treated or grasped by the prevalent method of analysis, so you’ll also need different sets of tools for the entirety of your life.
What worked a year ago might not work now because it is not a year ago, it is now, and you are not yourself from year ago but are a year different. There is no universal tool and even advice giving is a probability game where you give someone the benefit of your distilled wisdom and hope he/she can find something worthy in it for their particular situation. This does not mean that a wrench is more valuable than a screwdriver, or a screwdriver more valuable than tweezers. It depends on the job and the task. There is no one lever, as in a bad doomsday movie, you pull and it all comes together – you save the world, you save yourself. We cannot judge the adequacy or inadequacy of a wrench on the grounds that it is not a screwdriver. They both have roles to play and are applicable in different situations. Hammer is good only if you need to hammer something into place, if you need brute direct outside force concentrated at a small area. Some things might be used in its place of course to achieve the same result – if you’re creative a rock can do just as well – but there are more delicate things that cannot be handled by a hammer and you’ll sometimes need tweezers to get the result or you’ll need torque that only a screwdriver can give.
We don’t presume to know what you’re trying to build but we do know that you’ll need a whole proverbial tool belt to do it well. It’s extremely hard to fix things and not make them worse by just blindly whacking at it, but if you choose the right tools and show some determination you just might make it. Don’t be afraid of complexity, sometimes you just cannot fix everything with a hammer.