Sam had the ring for just a moment before he started fantasizing about leaving to come back with an army of hobbits to take mordor by force and making it into a garden. He barely managed to give it back to Frodo who had been carrying it all this time while it slowly chipped away at his mind having to constantly remind himself to not give in to its temptations while it was punishing him for not doing so with constant torment.

But sure he was just useless, go Sam whoo!