Alot was expected of Marut directly from his birth. The chieftain of the Rito tribe, Marut's father, was a strict and harsh man. Marut was raised from the get go to be a leader, taught and disciplined to be a wise and fair leader. He endured a rigorous upbringing, with his father remaining emotionally impartial to him for the sake of "appearing fair" to the clan. As such, Marut never really got close to much of anyone. He had no family to fall back on, his mother dying when he was little of illness, and without any siblings to rely on, sans on younger sister whom he had to care for in addition to his other duties.
As Marut grew, he realized more and more how he despised being kept on the island. A generally free spirited people, the Rito were uniquely blessed with being able to travel between islands without needing a boat; Therefore the idea that he had to be cooped up on Dragon Roost island his whole life seemed ridiculous. Several arguments between him and his father were started over this, and the two ended up becoming on rather poor terms with one another as a result. Still, Marut remained determined to see more of the world.
His chance came after his coming of age ceremony, when he recieved a dragons scale and with it his wings as a Rito. He didn't make his move initially; He waited several months, until his father was unsuspecting, and then bolted. He flew to the nearest island, but only stopped there long enough to get his bearings, before then departing that island, always on the move to see as much of the world as possible in as little amount of time as possible. Eventually he lost sight of the goal to actually enjoy the world, and simply started moving from place to place because that was what he was used to; And that's what he does right now.
Also he maaaaaay have taken the super important Din's Pearl, not realizing it was super important to the tribe. And then he lost it. Well technically Din magic'd it away from him, but it's all relative.