Gilbert's personatilties are very mixed up. At first he is very shy and kind oof keeps to himself, but later in the story we see that he is very carefree and a nice kid.
Gilbert's motivation is camly because he wasn’t really all exited about the things/items that he had brought to the place.
One life changing this is that his father dies, and he doesn't take it well.
The story really begins when his father passes away, when his father passes away he sees everything in a new light. The end of the story is when he is able to travel back in time and try to find his father.
By the end of the story Gilbert is still trying to look for his father.