What do people really mean when they say "Dont have too many expectations?"

Well as far as I remember it...I have never said it... I mean its not my natural thing to say that! But I know of a lot many people who say "Well dont expect too much" and say it way too often - even sometimes out of context... C'mon its the human nature to expect or atleast be curious of what the outcome will be for his actions/someone else's actions. And if you are an optimistic person, you are bound to have expectations. I mean what kind of person says, "well yeah I have done my bit, but I really dont expect much."

Even the most sage-like people I know have great dreams, great ambitions - they are brimming with boundless zeal and energy and am sure "Dont expect too much" is not their driving force.

So what's wrong with expecting the best, nothing but the best and fighting against mediocrity? People who expect are also people who can give, who can go that extra mile.. because they are conscious that they have expectations to live upto as well.  It doesnt scare them to try - well they'd die if they dont, because expectations keep them going, not so much the others' as much as theirs! And a person who doesnt set expectations for himself is living a lie... God save him..his life is a pity!

So next time, I am not going to let people look me down by saying "Dont expect too much"...I will just look back squarely and say - "I'm really sorry for you".