Sure the wizard had thousands of years but he would have gotten complacent. By the time he would have noticed anything amiss, the ring would be melted.
http://www.youtube.com/watch?v=1yqVD0swvWU
He knew it had been found. His minions missed nabbing it at Bilbo’s hole by a matter of hours. He wanted his friggin’ ring back BAD, and a few millennia wasn’t gonna slow him down.
Yeah, saw that one not long after the LotR movies came out. Hysterical and thought-provoking.