The lyfe so short, the craft so long to lerne —Geoffrey Chaucer
A man may write at any time, if he will set himself doggedly to it —Samuel Johnson
No writer ever truly succeeds. The disparity between the work conceived and the work completed is always too great and the writer merely achieves an acceptable degree of failure —Philip Caputo
Writing is necessary, not literature. (W. G. Sebald)
Which I take to mean that for people who must write, the writing is what counts, not the public side of publication and reception.