In the Copa America match between Peru and Brazil today (14/6/2015) Neymar added another goal to his grand total of 44 for the Brazilian squad, making him the 5th highest goal scorer in the history of Brazil. He has scored those goals in 64 games, and that at the age of only 23 years and 135 days.
It will take some time for Neymar to reach the top-3 of this table, but it will make him appear among Pelé, Ronaldo and Romario, 3 players which are generally considered among the top players in the history of football.
Considering the young age of Neymar and comparing him to those 4 giants, we see that Neymar leaves all of them behind:
In this related table you can see at what age the 5 scored their 44th goal for the Brazilian team:
To make it all complete a graph with the amount of goals they scored at each age: