Don't let your world of possibilities be determined by other people's opinions. Not in poker, not in life. Why? Because most people in the general population never went out of their comfort zone to see whats really possible. Most people are afraid to do that. And anyone else who attempts just that frightens them, because he reminds them of that very thing they try to avoid. Uncertainty.
Don't listen to the opinions of ANYONE once you have determined your way and you strongly believe you will do it. Don't let negative people put you down, even if they seem to come from competent places. But don't let praising comments cheer you up either. Because once you give a person power to make you feel better by praising you, you also give them the power to make you feel worse when they start criticising you. Only you yourself should have the power to uplift yourself or be critical of yourself.
Don't let the general consensus amongst any group of people be a determining factor of possibilities and achievable goals. It's a disaster if you do. Greatness is born out of individual imagination. It's kept hostage in collective constraints.
Utlimately, you need to challenge your own thoughts too. Because they too are a collective. They are limited. And they too might limit the picture you see of all the possibilities that are out there. Always be willing to change your point of view. Always be open to arguments that contradict your own beliefs and play them out in your mind. Always be willing to feel weaknesses inside yourself and investigate where they come from. Always keep learning. But always

Belive in Yourself