Well, you check memory very briefly, make a quick scan, and it's awfully easy to say to yourself, Ring, Rang, Rung, and very hard to say to yourself, Pare, Park: they come more slowly.
Vous consultez votre mémoire rapidement, et il est très simple de se dire : Ring, Rang, Rung, et très dur de se dire : Bare ... Park : ils vous viennent plus lentement.