Which is the most important document in our life? It would be Property documents or Qualification Certificates or Insurance policies or Share Certificates or Marriage certificate or Fixed Deposit certificates etc. There will be many answers depending on person's state of mind or circumstances. Back to the middle of 20th century and earlier, people were least bothered their birth date because, there were no questionable use of it, except a few people like Govt. servants, Teachers, Defense personal etc. Others, majority of people, only aware that they are living in their locality moving here and there and doing some kind of job or business.