Marcus is optimistic. This is one of the first personality traits he indirectly reveals about himself in his role as first-person narrator. The roof in the family home on the military base--a location he finds comforting ("there was something nice about living on the base and not with the civilians")--has a leak in it, and the leaky roof is over his bedroom. The rat-tat-tat of the "continued drip" of rainwater into the various buckets arranged about the room keeps him awake then awakens him too early. His response combines annoyance (who wouldn't be annoyed by such a sound) with good humored optimism. Instead of being negative, angry or gloomy he acknowledges optimistically that the sound is "almost musical":
The water continued to drip, hitting different buckets with different sounds. It was almost musical--annoying, but musical.
Another personality trait we can infer from what he reveals is that he is accepting and loving. He compares his ability to awaken to his own "internal alarm" to his father's ability to do the same. This shows that underneath his pride in being like his father is a deep acceptance of his father and an admiring love for him.
I had a strange internal alarm that almost always woke me up five minutes early. My father was the same.
Another important personality trait is his ability and willingness to adapt (many people, though willing, do not have the ability to easily adapt to hardship). From the wobbly kitchen chair and table to the houseful of needed repair work to making morning coffee for his mom to adopting little lies to ease the worry and distraught emotions, Marcus shows he is both willing and able to adapt to hardship.
[Mom and I] [w]e had an agreement--we'd both lie to each other and pretend we were sleeping well. It was part of a secondary lie--that we were't worried about Dad.