If knowledge had a copyright or patent we would have to have a seance to resurrect all of the great mathematicians and philosophers and get permission to use all of the basic concepts of our civilization.
Every child who ever wrote a book report would be in prison for sharing ideas learned in a book.
Everyone who ever 'carried the one' to the tens' column would be paying royalties.
Every child who learned test tube division would be paying fees to the estate of Maria Montessori.
Teaching would likely be prohibited as the royalties and releases would be prohibitively expensive.
Religious folk would have to ask the Lord's permission to put words from his book on their signature lines on this board.
Cite the reference, quote the book.
Now let's all laugh and get back to the sewing machine!