Ask any builder. While it may not be the prettiest part of a building, the foundation is the most important. Everything else is built upon it. It is the first thing built and it is the last thing left standing.
The same holds true when it comes to all of knowledge. Core truths must be established before one can understand the reality that we live in. For example, without the foundational rule of addition we would not be able to figure the sum of 2+2. Building upon that same rule, we know that 34+78=112. Addition is the foundation upon which mathematicians build.
So what is the foundation of "true knowledge"? Proverbs 1:7 tells us that it is fear of the Lord. Fearing the Lord means understanding that He is God and we are not. It means acknowledging the vast difference between the Almighty God and His fallen creation. Until we accept this foundation of truth, we cannot know anything else.
Unfortunately, Christians and non-Christians alike often prefer to minimize the Almighty nature of God in order to live lives that are not dependent upon him or in accordance to his ways. Instead of reducing God to our level we need to "fear God", and allow him to bring us up to his. We start this journey by entering into a relationship with him through his son, Jesus Christ.
May the Almighty God be with you.