"You earned, 'You Did It.' Trophy!"

 "Achievement unlocked:
50G - Finally Over. "

Nowadays with the PS3 and 360, it's easy for someone else to see that you've beaten a game. From simply telling friends, to people looking at your trophies/points, or even people reading it being published onto your Social Networks, it's no longer a mystery if you've beaten the game. However, some people go above and beyond that. When do you decide that you tell your friends that you've beaten the game? Is it when the game tells you you've beaten it, is it something of a personal accomplishment or something else?

Let's take an experience I had playing Dragon Quest 4 for an example. A friend of mine gave it to me to borrow since he knew that my DS was getting a bit lonely. As I played through the game, I experienced things I liked and disliked and eventually worked my way to the Final Boss. As I defeated him, cue credits and ending. However, something just didn't feel right to me about the ending. I searched frantically throughout the game, wondering what this feeling was. As I booted up my file, I realized that they had saved it for me after defeating the boss. "Hmm, a hint that something still needs to be done? Of course."

Without giving away any spoilers to the game, I eventually found my way and defeated the TRUE Final boss. I ejected the DS Card, returned it to my friend and began discussing the ending with him. Little did I know, that my friend had not gotten the "True" Ending. I told him of the events that I cleared in order for the true ending to be revealed. He replied, "Well, it doesn't really manner since it's not canon." Something about it not happening in Dragon Quest 5 or something that I didn't care too much to listen about...but I digress.

Although my friend had only gotten the normal ending, and myself the "True" ending, we both have beaten DQ4. The question is, "When do you feel that you've beaten the game?" Is it when the game tells you at the end of the credits, "Thank you for playing" or "The End"? Or is it more in the sense of self gratifaction and satisfaction with how you did?

(Don't get me started about Trophies/Achievements! That's for another day.)

tl;dr When do you put a game under your belt and say, "I've beaten this game." ?