To Accept Limitations or Not?

One of Freud's basic ideas was that the pleasure principle had to be replaced by the reality principle.  The baby's belief that it could have whatever it wanted (fantasy) had to be replaced by the reality that it has to do things to get what it wants, and that some goals and objects are simply not obtainable.

Manic persons can be delusional and lose sight of the reality of their limitations when they are manic, particularly in a psychotic mania.

But here is the problem.  When we accept our limitations, we automatically close off certain possibilities because we know that they will never occur.  It automatically becomes a self-fulfilling prophecy.  We know we cannot accomplish something so we don't try. 

Thus, as a psychotherapist, I have to struggle to walk the line between not giving patients false hope (e.g., becoming a nationally known singer) and not giving them the encouragement to reach their true potential. 

Last night I had the opportunity to listen to and talk to a jazz pianist who has only been playing five years.  He was going to be an military policeman when an accident injured him and caused a dramatic change in his life.  He has only been playing five years but is polished, professional, and a delight to listen to.  He takes lessons from a teacher in New York City and has performed in a jazz festival outside of Rome, Italy.  He has to struggle right now to feed his family (he still works as an Oklahoma City policeman) and practice and perform.  But he is almost there--almost to the point of being a full time jazz pianist.  He has a gift, and he will undoubtedly reach his goal.

Another person I know has built a multi-million dollar company in the space of a year's time.  At this point, it is not clear if there will really be a limit to what he can accomplish financially. 

So the question is, how are we to view the reality principle?  Are we to believe that we have limitations, or not?

One clue to answering this question is to look at the fact that one of the above persons is in his young 30's and the other in his late 20's.  So perhaps one way of answering the question would be to look at the age of a person.  I am in my sixties.  I have less energy than I used to.  And I have less time on Earth left.  So it would be best if I was realistic about what I could and could not accomplish.  Another clue to answering the queston is that both of the above men made some tangible progress towards their goals within a few years.  Other people may fantasize more than actually doing something. Both of the above men are full of energy and work hard at accomplishing their goals.

But I am left wondering, is it better to accept limitations or not?  Right now, I guess I just don't have the answer.