Why do?

As I'm sure that today's situation is getting me nowhere, I decided to think of it thoroughly. Why work? Why try? What is it that is worth?
The question: why people do something?

1. They want to have fun
2. They have to earn money and somehow survive
3. They crave for power and might
   
4. They want to be acknowledged
   
5. They have an idol and they want to be like him/her
   
6. They are workaholics
7. They seek for something interesting
8. They have dreams (what is my dream, by the way? it has been long since I thought about it...)
9. They are not satisfied with how things are at present
   
10. and so on

I just do not get something vital in this world, right?
I still have problems with motivation from time to time. I just can't do anything without a reason behind it. And "I just want to have fun" is not working for study.