As Sam, Frodo, and Gollum walked away from the gates of Mordor, Frodo jiggled the ring around his neck, the ring dangling from it's chain. Frodo had began to have a consuming feeling for the ring: like he didn't want to get rid of it, that it was his. Almost that it indeed was "his precious"
"Precious consumes Frodo, doesn't it?" Gollum said to Frodo, noticing his jiggling.
"How did you know?" Frodo asked, walking carefully away from Gollum so as not to get him too close to the ring. "Smeagol..." he added as an afterthought.
"The same happened to Gollum, yes. He loved ring, then it consume him. He try to destroy it, but Gollum can't, no!" Gollum/Smeagol said, a look in his eyes as if he was having a flashback.
"It changed you, didn't it? You didn't always look like that, did you? Or act like that... No, the Ring revolutioned you completely! You had it for five hundred years! I've only had it for a couple weeks!"
Gollum paused.
"Birthday present..."
"The ring? You got it for your birthday? When you were Smeagel. Who gave it to you?"
"No, no, no, Gollum doesn't know!"
"The ring changes you, Smeagol, doesn't it. It sucks you in: makes you want power."
By this point, Sam had stopped walking and was eagerly listening.
"Gollum wanted power, yes... He discover ring make Gollum invisible... Gollum steal... The ring make Gollum overconfident and depressed..."
(Frodo and Sam were both shocked to hear Gollum speak a complete sentence)
"Who did you steal from, Gollum?"
Silence from Gollum.
"Gollum... I need to destroy this ring as soon as I can, can't I? Or else I wouldn't want to anymore: I'll want it for myself, like you did."
"MY... PRECIOUS!"
And then, for the first time in six hundred years, Gollum shed a tear.
"Getting emotional, stinker?"
"Shut up, Sam!"
Gollum seemed to have shaken off his tear: he stood up and said "Entrance this way..." The party kept walking.