This isn't my personal theory, but a friend found it online and frankly, I feel as though it answers all of the mythology questions that bothered us most of all. Sicne it's not my theory I'll give you the URL so you can read it yourself.
It's long, but TOTALLY worth your time to a fanatic. Enjoy and lemme know what you think!
http://ericknowsitall.com/ultimate-lost-theory/Read more >
If in the 'alternate timeline' the bomb goes off, killing everyone on the island and indeed sinking it then Daniel and Penny are never born.
So in this alternate timeline, what is Desmonds new modivation/destiny? The love of his life doesn't exist and there is no button for him to press. He, above and beyond everyone else, has a completely clean slate.Read more >