Keep away from people who try to belittle your ambitions. Small people always do that, but the really great make you feel that you, too, can become great.
Whether or not you can never become great at something, you can always become better at it. Don't ever forget that! And don't say “I'll never be good”. You can become better! and one day you'll wake up and you'll find out how good you actually became.
A foolish consistency is the hobgoblin of little minds, adored by little statesmen and philosophers and divines. With consistency a great soul has simply nothing to do.
Everybody can be great...because anybody can serve. You don't have to have a college degree to serve. You don't have to make your subject and verb agree to serve. You only need a heart full of grace. A soul generated by love.
You have enemies? Why, it is the story of every man who has done a great deed or created a new idea. It is the cloud which thunders around everything that shines. Fame must have enemies, as light must have gnats. Do not bother yourself about it; disdain. Keep your mind serene as you keep your life clear.