I check everything so many times and usually lose sleep going over what I have packed let alone essentials like passports, and yes I too have dreams I'm at the airport and can't fly because something is missing.
This subject reminded me of a few years ago when my son went to Tenerife with his mates and one of them left for the airport early in the morning as he was flying home on a different plane. When my son realised his mate had took his passport by mistake he rushed in a taxi to the airport hoping to exchange passports but his mate was already on board as no one had noticed the difference.
After explaining the situation someone managed to exchange the passports by the skin of their teeth before the plane took off. Well when the lad arrived at Gatwick he was stopped by Customs and spent a couple of hours trying to make them believe it was a genuine mistake.