DNA should not be the only tool in your genealogical research toolbox. Family stories, records at home, published books, official records, etc. should be used together with DNA. The best way to answer research questions and get a complete picture of your ancestral family is to use as many resources as possible. While DNA “doesn’t lie” it is often not as specific as we would like. While paper records can contain outright lies or partial truths, they can provide details DNA does not. They can help you make sense of your DNA results–at least sometimes.
And even if you’ve researched paper records for years, don’t expect DNA to immediately solve all those problems you have. Sometimes it will specifically answer a question and other times it will simply tell you that “yea…those guys are related, but we’re not going to tell you exactly how.”
And when you don’t understand your DNA results, ask. There are a variety of online forums where questions can be posted.