I got a good lesson from regular meeting at my office.
Take a look carefully at the picture above! It has a small wheel labeled with number 1 and two other big wheels labeled with number 2 and 3. It also has two rubbers (4 & 5) connected each wheel therefore whole wheels can rotate smoothly and the system works well then.
Now, can you figure out which sub-system that is the most important to support the whole system? The answer is none. Each sub-system has crucial function hence every sub-system is important and none is more important than the others. Even for the bagatelle rubbers sub-system that have tiny size and light weight. Once the rubbers get burned or cut off then the whole systems certainly fails to work.
So, never think what you are currently doing in your career or job is less important or more important than others. What you do depends on others work and what you do is needed by others. Therefore be serious and focus on what you are doing right now!
I have problems on that though :(