‘Bilbo knew no more than he told you, I am sure,’ said Gandalf. ‘He would certainly never have passed on to you anything that he thought would be a danger, even though I promised to look after you. He thought the ring was very beautiful, and very useful at need; and if anything was wrong or queer, it was himself. He said that it was “growing on his mind”, and he was always worrying about it; but he did not suspect that the ring itself was to blame. Though he had found out that the thing needed looking after; it did not seem always of the same size or weight; it shrank or expanded in an odd way, and might suddenly slip off a finger where it had been tight.’
Amazing how much this resembles people’s feelings about their smartphones.