Eel
.(Anglo-Saxon, œl.)
Holding the eel of science by the tail. That is, to have an ephemeral smattering of a subject, which slips from the memory as an eel would wriggle out of one’s fingers if held by the tail.
“Cauda tenes anguillam, in eos apte dicetur, quibus res est cum hominibus lubrica fide, perflidisque, aut qui rem fugitivam atque incertin aliquam habent, quam tueri diu non possint.”—Erasmus: Adagia, p. 324. (1629.)
To get used to it, as a skinned eel, i.e. as an eel is used to being skinned. It may be unpleasant at first, but habit will get the better of such annoyance.