Nigeria, Jan. 26 -- A leader like Jacinda Ardern of New Zealand doesn't come in tens. Not even in twos. And so, it was such a bright day on 26 October, 2017, when she took office as New Zealand's prime minister.

She was 37-years-old and also the youngest head of government at the time. What's there not to love?

But now, more than five years later, she has announced the withdrawal of that special light as she resigns the position, stating that she "no longer had enough in the tank" to carry on in office.

"I'm leaving, because with such a privileged role comes responsibility - the responsibility to know when you are the right person to lead and also when you are not. I know what this job takes. And I know that I no longer have enough in ...