In The Five People You Meet In Heaven, Eddie was actually saving up money to study engineering in college. He loved the idea of building things even though his brother, Joe, felt that he didn't possess the aptitude for such an ambitious goal.
When the war starts, Eddie joins many of his countrymen by enlisting in the Army. Mickey, an old drunk, warns him that 'War is no game,' and to shoot if the situation calls for it. He tells Eddie that it's too much thinking about whether to shoot that causes soldiers to get killed. Later on in the story, we find out that Eddie's war experiences have led to (what we would describe today as) post traumatic stress syndrome. Because of this, Eddie gives up on studying engineering altogether.
All he knows is that something stepped in front of him, blocking his way, until in time he gave up on things, he gave up studying engineering and he gave up on the idea of traveling. He sat down in his life. And there he remained.