One way to break down a lifetime would be to think of it as two portions-- the part where the person became better, and the part where he coasted.
In a normal person's life, the getting better part would include everything from his first breath of air, as he learned how to see and feel and breathe, through school as he learned different things, and probably through the beginning part of his job as he developed a baseline proficiency in his trade. The coasting part would be most of his career, as he put his educational investment to work, and, of course, retirement.
There are a lot of ways to get better. You can learn new things. You can travel and see the world, thus gaining new perspective. You can build your personality. You can create a body of meaningful work. You can become more healthy and more fit. You can actively cultivate relationships with people.