Abdul recognized this tendency to get punchy about discoveries to which other people were indifferent. He no longer tried to explain his private enthusiasms, and figured Sunil would learn his own aloneness, in time.
Learning one's aloneness - wow, that is just profound. For people like Sunil who lives in a slum, the surroundings should define who he is and his interests (the interest of survival). If there's anything beyond that interest - it means aloneness.