creating and learning are different. it took the 4th 3 yrs to create the technical so mastering something your creating would take longer then teaching someone something you invented. i also agree with the 4th being narutos dad because it would give reason to why he was choosen. why narutos family was never really talked about because learning about his dad could make him aware that he sealed kyubi in him which he wasnt apose to know. also why naruto has a natural talent for learning hard jutsu's( but suck at the easier one)