Lost isn't about the island. It isn't about the mystery or the magic. About the smoke monster or the others.
It's about the characters. About them being
lost; spiritually, mentally and physically.
It's about us and everyone we know, finding who we really are in the most extreme situations.
It's about finding each other.
Age, race, religion, politics, wealth, health, anything you can think of is discussed, with the island being used as a catalyst.
Science versus religion; the ending catering to both sides of the argument without ever committing to a definitive answer from the creators. They let you decide.
Many people complain that the ending didn't make sense. That not all the questions were answered.
Firstly I'd advise you to listen very clearly to the exchange between
. Everything that needs to be told about what happened on the island and after the island is right there.
Secondly, not all mysteries need be solved. "What is the island?" is akin to "How did humans get here?". There is a scientific explanation and a faith based answer. The show lets you decide.
In the end, the characters that we grew to love, that we watched change over six seasons, we're no longer lost.
Because they found themselves and each other.