I'll start this theory by answering the question: Why does Desmond remember what Faraday told him outside the hatch about finding his mom in 2007 and not before?
Desmond does not remember what Dan told him until 2007 because "off Island time" was at 2007 when Dan told Dez in the hatch (2002?) to go find his mom. Off Island time keeps moving forward and the Island (which exists outside of time) can skip around through all the events that have occured at some point on the island with a turn of a wheel. The Losties in 1977 are in "1977" on the Island, but their "off island present" (as far as their bodies are concerned) is 2007. The Island creates the illusion of time passing with night/day, rain/sun, and a human's internal body clock makes the body age because it is calibrated to "off island time". Richard doesn't age because Jacob was able to put him in tune with the Island and cause him to exist outside of time.
When the Island is "jumping", off Island time keeps going, so no matter what period in the Island's history it stops at, the "off island time" will still be moving forward. So people could be at the Black Rock event in 1845, but if the "off island time" is 2007 when the island moves back, then the off-island time (in their minds) will still be 2007 even if on the island they are at an event that first took place in 1845...This is how the loops are created. However, it seems if you leave the Island in 1974 even if you started in 2004 and off island time was 2004 then you can visit the "off island" 1974 (like faraday going to ann arbor)..although maybe there is something special about Ann Arbor??
Jacob and MIB just sit on the island and exist outside of time and when visitors come they always dress a little different or come on a plane or a boat because off the island technology is advancing, fashion is changing. But on the island, outside of time, things stay the same..there is night/day, rain/sun but that is just an illusion created by the island - perhaps Jacob and MIB don't even notice these changes, maybe they can see through the illusion (like how Locke can predict the rain)..I guess we'll find out..
Desmond does not remember what Dan told him until 2007 because "off Island time" was at 2007 when Dan told Dez in the hatch (2002?) to go find his mom. Off Island time keeps moving forward and the Island (which exists outside of time) can skip around through all the events that have occured at some point on the island with a turn of a wheel. The Losties in 1977 are in "1977" on the Island, but their "off island present" (as far as their bodies are concerned) is 2007. The Island creates the illusion of time passing with night/day, rain/sun, and a human's internal body clock makes the body age because it is calibrated to "off island time". Richard doesn't age because Jacob was able to put him in tune with the Island and cause him to exist outside of time.
When the Island is "jumping", off Island time keeps going, so no matter what period in the Island's history it stops at, the "off island time" will still be moving forward. So people could be at the Black Rock event in 1845, but if the "off island time" is 2007 when the island moves back, then the off-island time (in their minds) will still be 2007 even if on the island they are at an event that first took place in 1845...This is how the loops are created. However, it seems if you leave the Island in 1974 even if you started in 2004 and off island time was 2004 then you can visit the "off island" 1974 (like faraday going to ann arbor)..although maybe there is something special about Ann Arbor??
Jacob and MIB just sit on the island and exist outside of time and when visitors come they always dress a little different or come on a plane or a boat because off the island technology is advancing, fashion is changing. But on the island, outside of time, things stay the same..there is night/day, rain/sun but that is just an illusion created by the island - perhaps Jacob and MIB don't even notice these changes, maybe they can see through the illusion (like how Locke can predict the rain)..I guess we'll find out..