1998 year.by :
I swear to my father to go to the store for bread.
“Son, can you count me?
Father, I am studying in second grade!
2015 year.by :
I swear that my son will go to the store for bread.
What if I was fooled? I only study in second grade.

— — —
2015-1998 = 17, and another 7-9 years (the second class at the time) a total of 24-26 years. And that, if you take all the same average age of second grade, his son was born at 15-19 years old. Per you were conceived by older people and your parents did more with you?