Don't part with your illusions. When they are gone you may still exist, but you have ceased to live. To live a fulfilled life, we need to keep creating the "what is next", of our lives. Without dreams and goals there is no living, only merely existing, and that is not why we are here.
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. When you are seeking to bring big plans to fruition it is important with whom you regularly associate. Hang out with friends who are like-minded and who are also designing purpose-filled lives. Similarly be that kind of a friend for your friends.
All you need in this life is ignorance and confidence; then success is sure. You can "already know for sure" things that could actually impede progress. Always be on the lookout for the things you did not know, that you did not know. Secondly, work on strengthening personal belief that a particular will be achieved regardless of any adversity that may show up, or evidence to the contrary.
Courage is resistance to fear, mastery of fear - not absence of fear. So many look to eradicate fear from their lives, when that is an impossible task. You can certainly experience moments in absence of fear, however accept that fear will be with you whenever you are in the process of living creatively. The challenge is to go ahead regardless, simply notice the feeling and manage being courageous.
A man cannot be comfortable without his own approval. There is nothing more satisfying than that sense of being completely "at home" in your own skin. When you achieve that as a natural state of "being", then you can finally look beyond yourself and fully contribute all your talents to the world.
When the mind goes beyond the thought of 'the me,' the experiencer, the observer, the thinker, then there is a possibility of a happiness that is incorruptible.
He had an uncommon fondness for cats. As an old man summering in New Hampshire, Twain even rented kittens from a nearby farm to keep him company until he returned home. "If man could be crossed with the cat," said Twain, "it would improve the man, but it would deteriorate the cat." There's always something about your success that displeases even your best friends.