Boris Pasternak said this quote

The unforeseen is the most beautiful gift life can give us. That is what we must think of multiplying in our domain. That is what should have been talked about in this assembly, and no one has said a word about it ...Art is inconceivable without risk, without inner sacrifice; freedom and boldness of imagination can be won only in the process of work, and it is there the unforeseen I spoke of a moment ago must intervene, and there no directives can help.