I mean there are no "shoulds" but...The Etudes are known to be hard but with proper technique they should feel comfortable (not tiring or uncomfortable) to play. Getting there can take time though and I think it's on your teacher to train your basic technique so you don't have to struggle with the Etudes.Your issue sounds more like one of memorization though. How's your music theory? The Etude you mentioned is fairly simple harmonically so you should be able to memorize entire beats, bars or even lines quickly, because you can recognize which chord it is, know how it fits together with other chords, and how the chord has been placed/positioned on the piano.So for example, if you recognize an A flat major chord, an E flat 7 chord, and a D flat chord, as well as some other typical harmonies and progressions used in A flat major, and know the base and melody, and note any alterations that happen to the basic chords, and know how these chords usually fit together you should be able to memorize the first page in maybe half an hour or probably less.Memorizing the Etude in a day or two's work is not unreasonable if you know what you are doing. Otherwise you have an exciting journey ahead of you to learn a bunch of useful tricks!