Most of the time, we don't know what we really want.  This is why quite a few people, at the end of the day, are not happy. 

I think now just about everyone probably will agree that we are neither in control of our situations nor aware of what we are heading to.  This is why correct attitude is so important for you can no longer set prerequisites of your happiness.  Because if you do, it is very likely you will fail.

I think we need to do our best so we won't have any regret at the end, and expect nothing in return.  You have been given the opportunity to take your shot so you had better make the best of it as this might very well be all you can get out of this endeavor.