People like for things to be simple. They try to convince themselves that things can be made simple and they will advice you not to over-complicate them. It's not their fault. Human beings evolved to be efficient, to consume as little energy possible to achieve their goals. If your image of the world is simple it will be cheap to compute what you should do next. But the world is not simple just because we want it to be. So don't be fooled that some people behave like they know enough. Most likely they are wrong. You never know enough. Learn as much as you can. But the resources are limited. Mostly try to understand what is important. Choose which do you think that are the important areas and have a deep understanding of the mechanisms that make those subsystems turn. Don't be fooled, this is an over-simplification, mostly we know only in retrospect what was important, but can't do much about that. Luckily, each one of us doing particular choices will cover a lot of gr...