At six the alarm went off. Karenin’s great moment had arrived. He always woke up much earlier than they did, but did not dare to disturb them. He would wait impatiently for the alarm, because it gave him the right to jump up on their bed, trample their bodies, and butt them with his muzzle. for a time they had tried to curb him and pushed him off the bed, but he was more headstrong than they were and ended by defending his rights. Lately, Tereza realized, she positively enjoyed being welcomed into the day be Karenin. Waking up was sheer delight for him: he always showed a naive and simple amazement at the discovery that he was back on earth; he was sincerely pleased.

….

At three o’clock that morning [after the operation], he suddenly woke them up, wagging his tail and climbing all over them, cuddling up to them, unable to have his fill.
It was the first time he’d ever got them up, too! He had always waited until one of them woke up before he dared jump on them. But when he suddenly came to in the middle of the night, he could not control himself. Who can tell what distances he covered on his way back? Who knows what phantoms he battled? And now that he was at home with his dear ones, he felt compelled to share his overwhelming joy, a joy of return and rebirth.

….

…. Nor had she ever asked herself the questions that plague human couples: Does he love me? Does he love anyone more than me? Does he love me more than I love him? Perhaps all the questions we ask of love, to measure, test, probe, and save it, have the additional effect of cutting it short… Tereza accepted Karenin for what he was; she did not try to make him over in her image; she agreed from the outset with his dog’s life, did not wish to deprive him of it, did not envy him his secret intrigues… But most of all: No one can give anyone else the gift of the idyll; only an animal can do so, because only animals were not expelled from Paradise. The love between dog and man is idyllic. It knows no conflicts, no hair-raising scenes; it knows no development. Karenin surrounded Tereza and Tomas with a life based on repetition, and he expected the same from them.

….

“He’s doing it for us,” said Tereza. “He didn’t want to go for a walk. He’s just doing it to make us happy.”

[The Unbearable Lightness of Being by Milan Kundera]

that made me so sad when i first read it