Profound subject matter can be encompassed in small space - for proof, look at any sonnet by Shakespeare!
I wanted to use what I was, to be what I was born to be - not to have a 'career', but to be that straightforward obvious unmistakable animal, a writer.
In books, as in life, there are no second chances. On second thought: it's the next work, still to be written, that offers the second chance.
An article can be timely, topical, engaged in the issues and personalities of the moment; it is likely to be stale within the month. In five years, it may have acquired the quaint aura of a rotary phone. An article is usually Siamese-twinned to its date of birth.
I don't agree with the sentiment 'write what you know.'... I think one should write what one doesn't know. The world is bigger and wider and more complex than our small subjective selves. One should prod, goad the imagination.
All writing is presumption, of course, since no one knows what it is like to be another human being.