Daneel considers this, even pausing (briefly) in the enjoyment of his pie. "I've always known that someone did create me, and that the Laws were inviolate. It wasn't a question of reward for a life well lived, but simple practicality. Attempts to break them were... highly uncomfortable."

Uncomfortable in an entirely different way from his minor experiences with pain, but uncomfortable nontheless. It's the best equivalent.

"I've witnessed robots break down entirely when they were unable to keep the Laws. Friend Giskard suffered that, in the end."

Friend Giskard. That is how one robot addresses another, on Aurora, as friend, admittedly a meaningless term between most robots, but Giskard... Giskard had been more, a true friend in every meaning of the word, and while Daneel has missed him, grieved for him in his own quiet way, he's now struck with a sudden wave of sorrow, human grief. If Daneel is a person, if he should have counted as a person before he ever woke up this morning, then Giskard did too.

Suddenly, tears are in his eyes -- actual tears -- and he doesn't know what to do about it.