adj.
frustrated that you can’t force yourself to remember something, even though it’s right on the tip of your tongue—wishing you could simply rifle through your own files directly, rather than having to toss random scraps to your team of mental archivists, who evidently need hours to sift through the pile before they come up with an answer, just as you’re falling asleep.
From pither, to dig lightly. Pronounced “pith-erd.”