Apart from the garbage truck, another aspect that a lot of people find puzzling is the SMILE at the end of the film.

I used to think that this was just one of those unexplained puzzles in the movie, which is down to the viewer to decide on its significance and meaning.

I do not really want to go along with the theory that everything after 1933 was an opium induced dream but the smile did seem to fit well with that theory. Noodles dreams of his past and his opium enhanced imagination conjures up that Max engineered the whole thing to pursue a lucrative career on his own. There is of course the deaths of his friends - but this was probably down to Max - and the rape of Deborah but in his imagination he has met her in the future and whilst she is a bit cold towards him, she is still on speaking terms with him and optimistically things may get better. His conscience is clear and he can smile again.

However after viewing the scenes again and looking at Noodles clothes and tie, this is total rubbish. Chronologically the ending smile comes before the scenes in the opium den at the beginning of the film. Noodles has seen the devastation caused to his friends by his betrayal and goes to the opium den to seek solace. He loosens his tie, lies down on the cot and initially the opium pipe brings relief and he smiles, as depicted at the end of the film. However gangsters enter the theater looking for him, the chinaman brings him an infusion to wake him up and coming round from the effects of the opium he remembers the deaths of his friends.

A great touch - the ending coming before the beginning.