Continuity mistake: In the beginning, when Michael Berg is sick on the street in Neustadt and is leaning on a wall to throw up, he's near a closed door and is positioned to the right of that door. Next shot, from inside, shows the door now open and he is leaning to the left part of the door. (00:03:15)
Continuity mistake: When Michael comes back with a bunch of flowers, Hannah is ironing. One second she's ironing a girdle (I think it is), and the next second she's ironing a bra.
Continuity mistake: As Michael stands, naked, facing the bath, Hannah stands behind him, naked also and with a towel, to dry him; all through this, water has continued to fill the bath, but, miraculously, it turns itself off.
Answer: It is confusing in the movie because it seems like she went from the ticket taking job to the SS job after refusing the office job promotion, which would require literacy. When actually her SS job was prior to the ticket taker job. Was muddled in the movie.