The other day I had to drop off a new prescription at the pharmacy. As the clerk, a young man, was entering it into the system he asked me to verify my name and address, which I did. Then, he asked for my birthdate. I responded "2/X/57" he started typing and repeated back "2/X/27?"
Occasionally when I'm with my nearly 90 year old father I'm confused for his wife or sister. I get that it is the gray hair, and find it amusing. I wasn't even offended that this young guy would think I was 30 years older than I am.
But, there is this way in which once you reach a certain age (not sure what it is) you become just "old." There is just not the same frame of reference for birth dates of people considerably older than you. I'm guessing this guy was in his 20's, 30's, tops. Any date before 1970 is probably just the same to him. He had no context to put 1957 in any different place than 1927, 1937 or 1947--they are all well before he was born--and just "old."
Time to get used to it!