In a December 1961 letter, two years before his death, C. S. Lewis reflects on the death of his wife.
To lose one's wife after a very short married life may, I suspect, be less miserable than after a long one. You see, I had not grown accustomed to happiness. It was all a 'treat,' I was like a child at a party. But prolonged earthly happiness, even of the most innocent sort, is, I suspect, addictive. The whole being gets geared to it. The withdrawal must be more like lacking bread than lacking cake.
--Collected Letters of C. S. Lewis, 3:1303