Ok, this is in response to the query posted on my first blog "Lesson of Life" by Ramkrishna. Even I have been exploring the answer of this for quite a long time. I hope the following satisfies you.

1) Setting a goal and expectation of result are two different things.
 
Take the case of Arjuna and Krishna in Mahabharata. Krishna tells Arjuna to fight even though that would mean killing his loved ones. Because that is the work assigned to him, that is his duty. He should not think what would be the result of his action- that all his loved ones would be killed. He should just do his duty of fighting. The goal of fighting the war was to win it. But while doing the work, that while fighting, one should think only of fighting and not about the result of war.

Ok, lets say person A wants to top his class. This is his goal. But while studying he should not think about whether he would top or not. He should just study. Even if he screws up the exam, he should not think that all his hard work got wasted and now he won't top the class. And if he does not top the class, he should not regret it. Even though he did not achieve his goal, but he did his duty of studying. It's like concentrate on the work at hand.

See when one says "Expected Result", one means Goals. I can set a goal and still not think about it while working. Leaving everything else, I just  work in the best possible manner I can without regretting anything.

Another way to look at the same thing is that for example, a person B has been enrolled in school to study by his parents. This person B can study, do his duty without bothering about the result. He could have no goals and still study well, because thats the work assigned to him.

2) One can hope, one can dream, but while working towards it, one should think of doing the work at hand well. One should improvise on one's work and not worry about one's goals and dreams. Motivation is same as doing work at hand well.

3)One can say that everything in this world is pre decided, but nothing in this world can be done without Karma. One can not even take care of one's physical body without exercising (karma). So, doing work is necessary.  Thats why one needs to work.


I hope this atleast tries to answer your queries.