While he does have a connection to the island and its mysteries, Ben's knowledge of the crash comes from other sources:
* The smoke monster: The smoke monster (often referred to as "the monster" or "the entity") has the ability to show people glimpses of the past and future. This is how Ben learns about the crash and the potential it holds.
* The Others: The Others, the group Ben is a part of, have been on the island for generations. They have knowledge of the crash and its significance, and they've been manipulating events to ensure the crash happens.
However, it's crucial to note that Ben's understanding of the crash is limited to the information he receives through these sources. He doesn't witness the crash himself in any of the episodes.