If we are wanting to be blessed in life - we are going to have to embrace two things. These things are the ability to be taught or instructed, and the ability to have someone correct or reprove us.
This proverb puts it right out there for us - the path of life is wide open for the one who heeds instruction. This means we need to be teachable! Note it is not just the ability to hear someone - but we learn to heed what they say. The word instruction is important for us to grasp here. The word means to be instructed and disciplined. The primary instruction that it speaks of in Scripture is that of a father. When we learn to be instructed and disciplined by our fathers - it carries over into all of life later. There is a general ability to receive instruction in general. The other major figure who instructs in this way is God. Therefore - if we struggle being instructed by our fathers - it should not shock us when later in life we are unteachable - not only by others - but even by God Himself. Remember this . . . how we deal with dear ole dad - is a precursor to how we will one day be able to deal with God or anyone else. Rebel against dad - it is more likely that you will rebel against others and God.
The second half of this proverb tells us that when we ignore reproof - we will go astray. The word "ignores" is the Hebrew word "azab" which means to forsake, abandon, or leave something. The idea is that of walking away - and not caring about someone. The word is used of those who forsake their wives - of those who abandoned their cities in a time of battle - and of those who forsake God. Reproof here speaks of someone giving us a rebuke, correction, or an argument that shows us where we have erred. The erring here is when someone forsakes the warning of God and goes their own way. They may listen - but they reject what is said - the reject the rebuke or correction. The end though is that they reject what is said and continue in the way that they want. We are warned that such choices will lead us away from God. We will make mistakes when we live like this - with an unteachable and unrebukable spirit.
None of us are born as unquestionable genius' who do not need instruction or correction. We all make mistakes and err in our thinking. That is why it is a blessing to have those who love us enough to offer correction and godly training. They become a source of protection and life to us. But if we never learn to accept such teaching and correction - we will ensure that we are on a path that will fail in the end. Therefore - listen! But there is more to this than listening alone - there is the need to hear with understanding and with a heart that embraces change. This, dear saints, is wisdom.