Always been told it ' s because brain development doesn ' t end until 21 , but at the same time that could totally be an old wives taleIs there any truth to it ? <| sep |> It didn ' t make much sense to me . Hamilton would have to push Nico backwards through both the Red Bulls and still come first to make that work . Bit too much of a risk if you ask me , especially with Mercedes giving pit strategy to the # 2 driver if threatened by an undercut from behind the team ' s best shot at maximising points is just to have both cars go all out . It ' s all academic anyway until the end of the first lap . Anything could happen in that time and change or completely invalidate any prediscussed strategies . <| sep |> Just get a PGC G 18 C slide .