Waiting in Vain (?

Hi, there! 

On this rainy day I am listening to´Waiting in Vain´ (Bob Marley´s song - shame on you if you don´t know that -) and suddenly I thought: Why do we always wait for things to come to us and knock at our door saying: "Here I am, finally I have arrived"! Well, as we are all grown-ups, we know that nothing in this world works in that way. 

Going back to the matter of ´waiting´, please do not misunderstand me, I know that sometimes we have to wait for certain things to happen but...Have you ever had that feeling of being waiting in vain for something? Do you think that waiting is useful? I think that we spend half of your lives waiting...waiting for the right moment, for a person to change, for our retirement to travel (and what if when we get retired our body is no longer able to carry us where we want to go, if our mind is no longer able to enjoy life, and what if there is not retirement, if the end hit us earlier than we expect it?)
Well, I get too pessimistic and that is not me. So, I will leave you with our friend Bob.  =) 
Ps: I´m eager to read your comments. 

https://www.youtube.com/watch?v=HgI3FpJHVAg