"People can be anything they want if they want it bad enough."

Was he meant to be a Sage? The seal on his chest suggested he wasn't. But he wanted to become a Dragon so badly and believed in his path so strongly, he was willing to do whatever it took to make his dream come true. Was his mother, also a male, meant to carry a set of twins? No. But he wanted to atone for the deaths on his hands that he was willing to do whatever it took to create life, for once, instead of destroy it. Was his brother meant to be Hokage? Yeah, probably. But he still had to work really hard to get there.