Our understanding at any point in time is always incomplete, but general good enough to work with and identify what we do not understand at present. We do not have to understand or consider everything which may effect behavior if we can bound the magnitude of the effect. It is critically important that you develop your tools. Learn to think clearly and rigorously and discipline yourself to do so. With suitable approximations, almost everything can be reduced to an engineering problem.
Technology is the embodiment of our understanding and control of the physical world.
Knowledge is good. Technology is good. I sat bolt upright. What I tell you about science should never be taken on faith. Each and every step should be proved by direct observation.