"a painter of painting"

My friend Palermo came by yesterday, with her out-of-print book on the complete works of Picasso's experimentation, as creator and destroyer, with Velasquez' painting of Las Meninas. A born rebel in an age rebels with or without causes (Castro, James Dean), Picasso became the first 20th century celebrity artist by dazzling peers, critics and investors with the Protean creative impulse exhibited here.

He had a legendary, colossal ego. Note that in the 1656 Velasquez, the painter himself is almost obscured in shadow and the royal toddler is the person in the spotlight. In the 1957 Picasso, the painter looms large and magnificent, out of proportion to other figures represented. Was Picasso paying homage to Velasquez, to painters in general, or just himself? Was this just a sign of the times, 300 years after Velazquez?

What I want to know is how much did that ego drive his innovation. Science has decoded genetic material for shyness, why not for ego? We could all use some if it came with some of that zest for breaking out of tired old molds.