"Twenty"

I remember when I was in high school, my literature teacher spoke about Pablo Neruda and introduced me to his books. I thought that Twenty Love Poems and a Song Despair was the most beatiful book I had read in my life.  Today I want to talk about the poem "Twenty".  This poem brings me back to my teenager days.
In "Twenty" the writer evokes with nostalgia his ex-girlfriend, but more than describing her, he describes the feelings that experienced. First, he felt loved, second, he felt in love. Is easy for the reader to percives loneliness and melancholy and how the pain intensifies thoughout he poem, finally acceptance of his loss.
I don't remember any special circunstances about this poem in my high school years,  I think ths is one of my favorite poems because of my romantic nature. This poem is significant for me because I shared it with my best friend, who shares my taste in literature and also thought it was romantic; so much that he gave me a book entitled Twenty Love Poems and a Song of Despair and One Hundred Love Sonnets the following Valentine's Day.

"Reunion"

Charlie wanted to see his father, whom he had not seen in three years. Charlie's father met him in the train station and Charlie thought he resembled him, and asked himself if he shared his same limitations. They went to a lot of restaurants, but they never ate anything because his father just ordered drinks in a nasty way and the waiters told them to leave. Time passed and Charlie had to go back to the station to catch his train. His father offered to buy him a newspaper to read on the train. He went up to a newsstand and spoke to the clerk in the same nasty way; the clerk didn't pay attention to him and turned away. Charlie said goodbye and went down the stairs to the train while his father insulted the seller in the newspaper stand, and that was the last time Charlie saw his father.

Questions:

1. Why was Charlie's father so nasty when he talked to other people?  

2. Was Charlie's father an alcoholic?

3. Was Charlie underage?