We generally don't have a complete understanding of something unless we know how it was constructed from nothing. If we start with the fact that it did not exist, and then from there we understand how it was constructed, then we feel confident that we indeed understand it. And sometimes we have to learn by our mistakes. Furthermore, we generally don't have an appreciation for certain things unless we know what need there is for it. For instance, devices are defined in term of what need they serve.
Necessity is the mother of invention.
And you have to find the problem before you can fix it. An example of the working of the principle above is demonstrated when in a trial, the prosecution may put an expert witness on the stand to assert that the defendant is not innocent. However, if the defense attorney can get the prosecution's witness to admit through some line of reasoning that the defendant could not have done the crime, then the defendant is innocent.