True art and true science possess two unmistakable marks: the first, an inward mark, which is this, that the servitor of art and science will fulfil his vocation, not for profit but with self- sacrifice; and the second, an external sign, his productions will be intelligible to all the people whose welfare he has in view.
In theory, cars are fairly simple. If they don't start, it's either the fuel system or the electrical system. Teach yourself about the path of each in your engine and tracing it is fairly straightforward. But at the beginning, mastering each new system seems like an unreachable shore. The car is effectively a black box.