“In infancy I was afraid of the dark, which I peopled with all sorts of things; but my grandfather cured me of that by daring me to walk through certain dark parts of the house when I was 3 or 4 years old. After that, dark places held a certain fascination for me. But it is in dreams that I have known the real clutch of stark, hideous, maddening, paralysing fear. My infant nightmares were classics, & in them there is not an abyss of agonising cosmic horror that I have not explored. I don't have such dreams now—but the memory of them will never leave me. It is undoubtedly from them that the darkest & most gruesome side of my fictional imagination is derived. At the ages of 3, 4, 5, 6, 7, & 8 I have been whirled through formless abysses of infinite night and adumbrated horrors as black & as seethingly sinister as any of our friend Fafhrd's [a nickname Lovecraft used for Fritz Leiber] "splatter-stencil" triumphs. That's why I appreciate such triumphs so keenly, I have seen these things! Many a time I have awaked in shrieks of panic, & have fought desperately to keep from sinking back into sleep & its unutterable horrors. At the age of six my dreams became peopled with a race of lean, faceless, rubbery, winged things to which I applied the home-made name of night-gaunts. Night after night they would appear in exactly the same form—& the terror they brought was beyond any verbal description. Long decades later I embodied them in one of my Fungi from Yuggoth pseudo-sonnets, which you may have read. Well—after I was 8 all these things abated, perhaps because of the scientific habit of mind which I was acquiring (or trying to acquire). I ceased to believe in religion or any other form of the supernatural, & the new logic gradually reached my subconscious imagination. Still, occasional nightmares brought recurrent touches of the ancient fear—& as late as 1919 I had some that I could use in fiction without much change. The Statement of Randolph Carter is a literal dream transcript. Now, in the sere & yellow leaf (I shall be 47 in August), I seem to be rather deserted by stark horror. I have nightmares only 2 or 3 times a year, & of these none even approaches those of my youth in soul-shattering, phobic monstrousness. It is fully a decade & more since I have known fear in its most stupefying & hideous form. And yet, so strong is the impress of the past, I shall never cease to be fascinated by fear as a subject for aesthetic treatment. Along with the element of cosmic mystery & outsideness, it will always interest me more than anything else. It is, in a way, amusing that one of my chief interests should be an emotion whose poignant extremes I have never known in waking life!”

Letter to Harry O. Fischer (late February 1937), in Selected Letters V, 1934-1937 edited by August Derleth and Donald Wandrei, pp. 416-417
Non-Fiction, Letters