Apply your heart to instruction and your ear to words of knowledge.
(Pro 23:12 ESV)
Notice how we are supposed to “apply” our hearts to instruction. It is not merely a matter of being open to instruction if it happens to fall in our laps, but we should seek it out. It is our responsibility. Instruction and knowledge take effort and we need to put in that effort. That is why I dedicated an entire chapter in Arguing with Friends to listing resources for the interested reader (i.e. the reader who takes proverbs like this one seriously) to seek out their own personal edification in life’s biggest questions. It’s your job, do it!
I need to offer a quick clarification about “heart” because our modern Western sentimentality associates heart almost exclusively with emotions. In the Hebrew understanding heart included emotions, of course, but also included the intellectual and moral facets of humanity. This is why a heart can be instructed – something more closely associated with our mind than our emotions. Most good Bible dictionaries will explain the Hebrew understanding of human nature more fully; look at that I’m assigning homework!