Before we definite the word "motivation", let's have some questions.
1. Why do you put on your pants after you get up?
2. Why do you eat everyday?
3. Why you hang out with your friend sometimes?
Do you have any idea about these questions? What makes us do things? What motivates us? What is motivation?
A Psychology teacher of mine gave us the answer:Motivatio is the process that initiate, guides,and maintains goal-oriented behavior.
There's a very well-known theory called Evolutionary Theory which says that we are motivated to do things to survive. That's why though new-born babies know almost nothing, they cry, drink, breath and grab.
Of course, we are motivated by higher level things. There's another theory which says: We are motivated to do things that reduce our drives(that get rid of our needs). For example, we sleep to get rid of our tiredness.
From my point of view, people have different experiences to motivate them differenly. To face one question, there sometimes can be more than two questions(if there are many choices).
If you were in a boat with your two children, one was one year old, the other was five years old. If the boat get sank, and you can only save one child. Who would you choose?
If you were in the same boat with two children of your own, one was forty, the other one is twenty. The same thing happened , who would you choose?
According to what you just chose, as Maslow said: We are motivated by 5 levels of needs: physiological, safety, love, esteem and self-actualization.
Now, do you know what makes you chose and why people do things?