Discuss this quotation: "nobody ever lives their life all the way up except bullfighters." how does this foreshadow jake's afición values? why does jake feel life must be lived to the fullest? how does the "lost generation" fit into this attitude?

In this interaction between Jake and Cohn,

[Cohn:] “I can’t stand it to think my life is going so fast and I’m not really living it.”

[Jake:] “Nobody ever lives their life all the way up except bull-fighters.”

Jake has made up to live his life the way it comes. He tries to advice Cohn to do same too.

The statement of Cohn above reveals the dilemma of the "lost generation". After World War I, young men and women began to feel that their lives were purposeless and directionless.

Such dilemma prompted Cohn to make such statement. But Jake who has made up his mind after the war to live his life like a bullfighter. He advises Cohn that “nobody” feels fulfilled in their lives, except a small group of extraordinary people.  Jake was simply advising Cohn to learn to live with his feeling of discontent which he, Jake has made up his mind to do. The advice demonstrated Jake’s character. He has come to accept his flaws and live by them.

Jake lived through the war and was significantly affected by it. He suggests that the only way to live life to the fullest is to constantly confront death, like a bullfighter.

As as result, he and his friends try to cure the unhappiness and discontentment they faced through constant travels, from bar to bar or from country to country. Jake knew that such are futile and purposeless.

The "lost generation" show a character of mentally, emotionally and morally lost people who are psychologically discontented. Their lives have no meaningful foundation.

They try to fit into the conception of the bullfighter with a belief that experiencing life in different settings and conditions might make one to "live his life all the way up". Their sense of discontentment made them loss emotional commitment and control and led to believe that by continuing to experience life in different contexts, some stability could be discovered.