Each day became precious to me

 From Fyodor Dostoyevsky's The Idiot

Prince Myshkin speaks with Aglaya, Adelaida, Madame Yepanchin.

"Prince, Find me a subject to paint." 

"I don't know anything about that. It seems to me that one should look around and then paint."

"I don't know how to look."

"Why are you talking in riddles? I can't understand a thing," interrupted Madam Yepanchin. "What do you mean you don't know how to look? You have eyes, you look. If you don't know how to look here at home, you won't know how abroad. You'd better tell us how you looked at things yourself, Prince."

"Yes, that would be better," said Adelaida. "The prince has learned to see things abroad."

"I don't know. All I did there was care for my health. I don't know if I learned to see. But almost all the time I was very happy."

"Happy!" exclaimed Aglaya. "Do you know how to be be happy? Then how can you say that you didn't learn how to see? You can teach us."

"Do teach us, please," laughed Adelaida.

"I can't teach you anything," said the prince, laughing also.  "Almost my whole time abroad I lived in the same Swiss village. Only rarely did I take short trips away from it.  What could I teach you? All I did at first was not be bored; I soon began to get better. Later, each day became precious to me, and more precious as time went by, until I began to notice it. I went to bed feeling very contented and arose even happier still.  But why this was so, it's rather hard to say."

A couple things seem important here.  First, the connection between "seeing" (as an artist sees and finds things worthy of painting) and "happiness."  Seeing truly is related to appreciating things around you (a donkey, the sound of a waterfall, resinous pines) and living fully.

Second, there's a connection between "taking care of my health" and "being happy."