What does Proverbs 10:8 mean?

The person who sincerely seeks wisdom is teachable. He recognizes that he does not know everything about everything. He longs for good counsel. By contrast, the unteachable person is coarse and hardened, so busy chattering that he doesn't take time to listen to wise counsel. As a result of his unwillingness to accept godly commandments, the "scoffer" (Proverbs 3:34) will come to a deplorable end of life.

Proverbs often contrasts the approach of those who sincerely desire wisdom to the attitude of those who refuse to learn (Proverbs 9:7–12). James 1:19 instructs us to "be quick to hear, slow to speak." The fact that we have two ears but only one mouth ought to remind us to heed James's instruction. When Jesus visited the home of Mary and Martha, Mary sat at His feet and listened to His teaching. When Martha complained that Mary wasn't helping her with serving, Jesus replied, "Martha, Martha, you are anxious and troubled about many things, but one thing is necessary. Mary has chosen the good portion, which will not be taken away from her" (Luke 10:42).