Just as I woke up this morning, I wondered, "Did I just have a very good night's sleep?". I had not slept this sound for sometimes. Not until last night. I don't know myself why or how could that happen.
Amazingly, an answer comes straight to me. I read Proverbs 3 (The Message). In verse 24, it says, "You'll take afternoon naps without a worry, you'll enjoy a good night's sleep".
Who's the 'you' here? I guess, it's the friend who guards Clear Thinking and Common Senses with his life; and never loses sight of them for a minute (verse 21).
So, answer to the question is CT + CS.