"Ever tried. Ever failed. No matter. Try Again. Fail again. Fail better." - Samuel Beckett
A site that lays out the spectacular failures of successful people.
And for reasons unclear to me, I think this piece fits - there's something wistful and regretful about it, but at the same time it's clear and beautiful, and becomes light-hearted sometimes.
The Finale of Haydn's Sonata No. 53 in E minor.