(CNN) -- Winston Churchill, glaring, resolute, combative, left hand on hip, stares straight off the page -- a moment, and an image, like no other. 

(How did the photographer, Yousuf Karsh, get that iconic pose from Churchill, Britain's prime minister, in 1941? Churchill told Karsh that he had very little time for the session. Karsh reached over and took Churchill's cigar from him -- then, as Churchill reacted, snapped the photo.) 

Marilyn Monroe, at her most beautiful in 1953, leans back, wearing white slacks and a black sweater, and gazes off dreamily to her right. Somehow, even though being photographed for a national magazine, she appears supremely relaxed and right at home. Why? She was at home -- she knew that the photographer, Alfred Eisenstaedt, and the magazine, Life, would do right by her, and she had invited them in. 

Prisoners at the Buchenwald concentration camp in 1945, their faces haunted, their bodies gaunt, their eyes showing nothing and everything, look out from behind the wire fence that imprisons them, just before they are liberated. How did Margaret Bourke-White happen to be there to shoot that photo? Gen. George Patton wanted the world to see why his soldiers were fighting. Patton understood that Bourke-White and her magazine -- Life -- were the best way for the world to witness and understand. 

All these photos and hundreds more are in a book called "75 Years: The Very Best of Life." It was published just before the holidays; I bought copies for friends around the country, and all of them have told me the same thing: They are spending hours with it, looking for long minutes at individual photos, treasuring the talent of the photographers, many long dead. 
How long did friend say they spent with the book?
They are spending hours with it,