The things you want are always possible; it is just that the way to get them is not always apparent. The only real obstacle in your path to a fulfilling life is you, and that can be a considerable obstacle because you carry the baggage of insecurities and past experience.
Of course we all have our limits, but how can you possibly find your boundaries unless you explore as far and as wide as you possibly can? I would rather fail in an attempt at something new and uncharted than safely succeed in a repeat of something I have done.
Every one's got it in him, if he'll only make up his mind and stick at it. None of us is born with a stop-valve on his powers or with a set limit to his capacities, There's no limit possible to the expansion of each one of us.