Board Thread:Theories and Speculation/@comment-5012682-20150620162706/@comment-24757127-20150630051637

Thekillman wrote: We also don't know what the normal age is to perform this jutsu, as Itachi was a genius who was Anbu by, what, 12 or so?

The Uchiha learn the Fire Release: Great Fireball Technique early in life since both Sasuke and Obito learned it before going to the Academy. For the Uchiha it might be tradition to master the Great Fireball Technique before starting the Academy. This could contribute to why the Uchiha are known for being a battle-oriented clan. The clan train their youth techniques before joining the Academy while I bet other kids are not learning ninjutsu yet and definitely not practicing techniques that use any elemental nature chakra.

It's interesting Sasuke learned a Fire Release technique so early when it wasn't his natural affinity. This probably contributed to him being called a genius. Possibly same with Itachi since he knows Water Release as well. We don't know if Water Release is his natural affinity though.