Quick answer
Sense earns goodwill. The second line's word is unusual, and translations reach for different things.
Read both lines
The NKJV footnotes the first verb as gives, so good understanding produces favor rather than merely deserving it, which fits this book's practical bent: people respond to someone who thinks clearly. The second line contains a genuinely difficult word. The NKJV renders it "hard," others reach for "rugged," "their ruin," or "does not last," and the term itself is unusual enough that the honest report is that translators are working with limited evidence. What survives every rendering is the contrast: one road is smoothed by good sense and the other is not.
Related: Proverbs 3:4 · Proverbs 12:8 · Proverbs 4:18–19
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.