can some one help me solve this riddle?

[Jordan]

if a boy was born in 1978, how is he only 18 years old today?
he did not die and no he was not born on a leap year

 

[Bram]

Born on a different planet

 

[LauraKeane]

the hospital he was born in was called 1978.

 

[Dave87gn]

he died

 

[Lizzi]

I think it's because he was born on leap year.