Compliments are best when they come from someone else. Likewise, the best proof isn't through mere words but through action. Let the results speak for you. Therefore, if someone claims something can't be done, do it. If someone claims you are such and such, be someone different and better. If someone tries to criticize or put you down, sincerely compliment him or her. How can you be down when you are in fact trying to pull everyone up?