@ Fisherman & others: "...the sign of the last days..."
Almost 2000 years ago, John wrote, "Furthermore, the world is passing away..." (1 John 2:17)
The day I was born (several decades ago) I began "passing away" - but I wasn't in my "last days."
If a doctor finds signs/proof that I've got a terminal illness which is about to cut me down, then I'll know that I'm in my "last days."
If/when we see Biblical/divine evidence* (not 140 + years of speculation) that the prophesied "last days" have started, the whole world will become aware - not just Christians. (IMO)
* Revelation 17:17 assures Bible readers that the governments of the world will delegate some of their authority & decision making powers to a singular new entity. (something similar to what many non-believers think today. NWO?)