What was the secret that Locke told Walt in The pilot episode by Republicworldwide

I have a theory that whatever Locke told Walt on the beach in the pilot episode ( when he was explaining the history of Backgammon). may be the secret ending of the show. I've heard theories about how the season may end with the opening scene of the pilot episode with Jack laying unconscious in the bamboo forest then running towards the beach. That scene is amazing and when you re-watch that episode pay close attention to the black tube at the top right of Jack's head and think about the possibility that the cut in his side (the one that kate stitches up) isnt from the plane crash but from some event that culminated in his waking up in the bamboo forest like he did. Far away from the rest of the losties. ( I apologize if this had been covered. I read this site every day and havent really heard this subject come up in a long time and i think they are important. I would love to hear more thoughts about what Locke s! aid to Walt and what that thing was lying next to jacks head.)

For years I had never seen lost but a few months ago I spent a week and a half watching every episode from the first to the last of the 5th season. Now ive been watching with anticipation as the story continues each week in season 6.
Ive gone back over every episode twice by now and I can tell you this- there was once an episode with a blonde teacher in 1977 teaching a dharma classroom full of children about the volcano at the center of the island. I really wish I could hear more about this from my fellow last fans. Mark my words- that volcano is gonna spew and that is going to sink the island. Im really surprised that so few people have mentioned this How that plays into Widmore and Locke and Jacob I have no idea - I guess we will find out eventually but im starting to think that no one will replace jacob or MIB and that the purpose of telling this story is that it is the grand finale or last run of the game. We are about to see checkmate game - one way or another.