.
Let me tell you even more:
(Almost) every parent (under reasonable assumptions) once is exactly twice as old as his or her child.
Indeed, if the parent brought a child when the parent was X years old,
then after X years the parent will be 2X years old, while the child (the son or the daughter) will be X years old
with the ratio of ages exactly 2.
The natural condition of feasibility is that they both are live at their corresponding ages.