Eckhart Tolle wrote The Power of Now years ago. Mine has a copyright date of 1999 and I have bought and given away many copies since then. I have read thousands of books on matters spiritual, philosphical and magickal over the years but when someone gave me the Desert Island book question I said that the only two books I would need would be The Power of Now and the Complete Works of Shakespeare. The querent was horrified that I didn’t pick The Holy Bible.