Pessimist vs Optimist

People say,

"The optimist invents the airplane and the pessimist the parachute."

So... my question is.. which one do we need to be?..

people always say that being optimistic is the key of success..

4 me... if u're being pessimist u're are closer 2 reality rite?

to make it simple i'll just do a simple comparison between those 2...

( note that the first one is for optimist n other is pessimist)

• brought +ve effect to mind VS -ve effect to mind
• day dreamer VS dream crusher
• problem solver VS problems finders
• inventor VS innovator 
• see problems as opportunity VS see opportunity as problems
• expecting miracle VS expecting bad consequences 

so..what do u think?? is being pessimist is better or optimist?

both attitude are vital in our life.. is like the yin n yang..

both need to be balance.. being balance is what realistic is about.. hope for the best and think for the worst..

when u're too pessimist u'll be miserable..

n if u're too optimist, people say u're delusional..

so guys keep the yin n yang in balance.. we dont wanna become miserable or delusional rite..?

Stay realistic and dream for the miracle...