I kind of understand why Picasso said that I have been learning painting from children all my life. His small realistic skill is very strong, and later he began to change his style ~ maybe he should know painting techniques to better express his childhood fantasies. Children's paintings, untrained and unconstrained, are often the most direct, while adults' paintings have no rules, so they are the most free and expressive. But as an artist, I personally think these are all a process. This is probably what the so-called return to nature means.