Vague To No Definition

One of the realization that I made during adulthood is to realize that achievement is such an abstract concept. For quite some time, i guess until my early 20, I thought life is kinda like video game:

• There is clear leveling so you complete one level (elementary school) then go to next level (junior high). Rinse and repeat until death comes.
• As the consequence of clear leveling, there is clear definition of accomplishment and achievement.

I realize later that this "comfort" of clear definition only exist as long as I'm in the education "pipeline". Complete this level, graduating, then move on to the next step. Rinse and repeat.

In the "real life", things has very vague definition. Take career for example: how do you know what level you are now? How do you define what is the requirement for completing current level and moving on to the next level? What is the next level? And even more importantly: is moving on to next level is necessary? when should we stop and know when things are sufficient?

All of this are vague; I need to figure out then make the definition of these stages for myself. I need to read, recognize the pattern, and ask myself what is my goals; Are they a worthy goals? Then, what are needed to reach those goals. Then, how to reach those goals.