You will live your billionth second when you are 31 years old.Some of you reading this might have passed your billionth second if are your age is 31 or more,for those who haven't wait for the moment.
Still not sure ,
Lets do math
100000000 seconds=277777.778 hours=11574.014 days dividing it by 365.25 we get 31.688 years.
If you want to find the exact hour of your billionth second go to this this link.