I guess this is a "thing" like post count and cock size and so on. But if you are interested to see how old your gmail account is, check by looking at your settings/pop settings. It gives the date pop was enabled and when your gmail was created.
I created my gmail account from an invite that you needed when gmail was still in private beta.
Mine:
I created my gmail account from an invite that you needed when gmail was still in private beta.
Mine: