Children need the security of knowing that we (parents and teachers) believe in their capabilities. Even if it is the “craziest” idea, we should never discourage their creativity. Instead, we need to encourage them to prove themselves to themselves; they owe us nothing and therefore do not have to prove anything to us. Give them room to explore their ideas and theories (as long as it’s safe and healthy). Allow them to learn as much as they can about their interests (i.e. books, movies, museums, etc.). And most importantly, show interest in what they are interested in.
When they lose interest, move on with them; take comfort in knowing that they just learned something new. When they believe say, "I believe!" When they fall say, "Try again." And when they succeed shout, "I knew you could do it!" Why? That support will be the fuel needed for their rockets to go farther than ever imagined. Regardless of their age, every child deserves to know that they can accomplish whatever they set as a goal (again, safe and healthy). Trust in your creation and just believe.