As a child, Segun Olagunju prayed for wisdom, which is the only thing that can explain a 20-something recognizing that if he’s going to make a difference in the world (Nigeria, in particular), he’s going to work backwards from being a 50-something changemaker in 2035.    Setting out on a 30-year journey to learn business, leadership, French and return to his home country strategically, Segun realizes the path is anything but straight.    Worse, it’s anything but *forward.*    Through a series of humbling experiences (“only out of humiliation comes humility,” he says), Segun learns that if you’re pursuing a meaningful purpose in life, these setbacks are minor blips—and even…