This film is about a welder who discovers some drug money and goes on a run from the reclaimers. The film is therefore mainly a warning against greed.
The main character of the film is Anton Chigurh, who goes about his daily business and becomes involved in reclaiming the money stolen by Llewelyn Moss. He is meticulous and patient, being careful never to leave evidence when he kills, and hunts his target relentlessly.
However, he is also shown to be prone to anger, and his philosophy of life, fatalism, is immature and fundamentally flawed. When he talks to the man at the gas station, for example, he seems to get carried away with intimidating the old man to no useful purpose. He also tried to intimidate the woman into giving him Llewelyn's work address to no avail. His conversation with Carson Wells was also rather gloating and did not serve any useful purpose.
The other characters in the story mainly serve as foil to Chigurh's character. Llewelyn Moss is a rather foolish character who decided to steal drug money for himself rather than reporting it to the police. He also does not like talking to people, unless they're hot girls.
The police are incompetent as usual and Ed Tom Bell is clearly suffering from senile dementia as he cannot even remember the stories that he made up just a few minutes ago. His complete failure to capture any of the gangsters pursuing Llewelyn Moss is therefore no surprise. The old men he talks to are usually just as senile as he is.
The story is probably more about senile dementia than anything else, going by its title. The old men in the story reminisce about the "old timers" unable to realise that they ARE the "old timers". They don't do much else.
Whilst the audience might be impressed by Anton's first-aid skills they might do well to remember that this is the same man who tried to use an Uzi as a sniper rifle (when he had a full-length shotgun), and unsurprisingly missed all 12 of his clear shots at a wounded man, and managed to get shot in the leg by his own prey.
All in all an ambiguous film that leaves much to be desired. The fatalistic philosophy comes across as rather pretentious and superficial. None of the characters in the story are competent to any degree, although this is still over 9000 times better than Superman Returns.