cross that person off your invitation list.
You will not do incredible things without an incredible dream.
Exceptional thinkers ignore their critics and go about their business making history.
We must not sit down and wait for miracles. Up and be going!
History shows us that the people who end up changing the world - the great political, social, scientific, technological, artistic, even sports revolutionaries - are always nuts, until they are right, and then they are geniuses.
As soon as anyone starts telling you to be "realistic," cross that person off your invitation list.