Artist's creation and thinking process.

Art is mysterious and attractive, but sometimes difficult to understand. Especially, contemporary art is strange. I have lived as an artist for 30 years in that strange world. Some contemporary artworks look unfinished but are completed works. Or an artwork might be just a collection of garbage, but it is collected by a beautiful museum. How does a contemporary artist think and create a work? Also, what kind of aesthetic sense is required in judging a work, and distinguishing between finished and unfinished works? Or, what is the relationship between the concept and the physical work? Also, are the values of contemporary art completely different from those of Classical art, like that by Leonardo da Vinci or Rembrandt? I try here to describe the question about contemporary art and the thinking process required to make an artwork. It's a very complex process and judgment, but it's never a mystery or miracle; it's based on an accumulation of human aesthetics and many years of experience.