Curious...
Last year I was departing Dhaka, and the Indian businessman in front of me put his passport in the security bin. It was very worn...and over 1 inch thick. At first I thought it was simply one of those mini Bibles or Quran, but then I saw the cover. I joked with him that that was the thickest passport I've ever seen. He said he travels internationally a couple times a week. I don't know how they got all those pages in there, or why the Indian government doesn't issue a new passport after a certain point.

Regardless, I kick myself for not asking the gentleman if I could take a photo. I try to fly politely, but sometimes I second guess myself.