Writing is tiring work

G K Chesterton writing to his friend, Bentley, not long after GK started his first job working for a publisher - Redway, mentioned in the letter. 

There is that confounded 'Picture of Tuesday' which I have been scribbling at the whole evening, and have at last got it presentable. This sounds like mere amusement, but, now that I have tried other kinds of hurry and bustle, I solemnly pledge myself to the opinion that there is no work so tiring as writing, that is, not for fun...