Audacity.

Churchill, Self-Portrait, 1920

If ... you are inclined - late in life though it be - to reconnoitre a foreign sphere of limitless extent, be persuaded that the first quality that is needed is Audacity. There really is no time for the deliberate approach. Two years of drawing-lessons, three years of copying woodcuts, five years of plaster casts - these are for the young. They have enough to bear. And this thorough grounding is for those who, hearing the call in the morning of their days, are able to make painting their paramount lifelong vocation. The truth and beauty of line and form which by the slightest touch or twist of the brush a real artist imparts to every feature of his design must be founded on long, hard, persevering apprenticeship and a practice so habitual that it has become instinctive. We must not be too ambitious. We cannot aspire to masterpieces. We may content ourselves with a joy ride in a paint-box. And for this Audacity is the only ticket.

Sir Winston Churchill, from Painting as a Pastime