The autobiographical poem "The Story of Lost Friends" is Ruskin Bond's allegorical rendition to his sad childhood.
Basically, Ruskin was very small when his mother abandoned he and his father for another man. Not only was this a shocking social choice, but it left a huge mark in the life of both Bond and his father. As a result of the mother's abandonment, father and son learned to grief together, becoming extremely close. Ruskin held his father in high esteem, since his father was both mother and father to him.
However, the saddest thing happens: Ruskin's father dies. As he is sent to boarding school, he begins to experience long bouts of depression and loneliness that only got worse with time. Summers away from boarding school meant that his time would have be spent with his mother and her new husband.
The drive on the train to his mother's home in Dehradun is what the poet refers to as
a long journey through a dark tunnel
He was never welcome at the mother's home. Nobody was there at the station because the mother assumed that the train would be late as always. And, to top it all, he basically was told that he would ruin everyone's daily routine.
As he entered the home, he was shocked at the newness of it all, which is why he uses the word repeatedly. Suddenly, he was in a new home, and now he had a little brother to boot.
Hence, the poem moves on to focus on the friends that the poet lost as a result of his dysfunctional home. First it was the boy with the "blackberry eyes" with whom the poet enjoyed respite only to be scolded for staying over his house, breaking the friendship for good.
Then, the poet befriended the soul of a tree, wandered through cemeteries, and continued reminiscing in the sadness of his childhood. The poet even befriended lepers from a community which, of course, causes dismay in his parents...and that friendship also ended.
Finally came Manohar, the village boy, who helps the poet escape. However, his step-father's secretary is sent to recover the poet, who says good bye to his "bright boy in the mountain side", forever.
At all times we sense a deep feeling of grief and mourning; of incompleteness that permeates the poet. He grew up a lonely boy, in a sad household, and losing friend after friend. The biggest friend lost was obviously his father. Then Manohar. But he always searched for that one boy he saw once in the train station waving cheerfully at him, although he did not know him. It is simply the poet telling us how he, also, searched for the happy boy within him.