When to stop?

I have always believed there is a silver lining in everything, either good or bad. Every time I lost a dream I made up my mind to fight back. I looked up again and thought I can do it.

But some dreams never come true. Some goals can never be shot. May be some things that you desperately want are never really meant for you.

If so then I cannot sit but wonder how do you know you are not in the right direction. When do you know that the goal you are striving to achive can never be realised. When do you know that you should stop? When do you know that its time to move beyond...