Final answer:
Mr. Dussel is expressing his shock at being persecuted in his own country where his family has lived for generations, highlighting the displacement experienced by Dutch Jews during the Nazi occupation.
Step-by-step explanation:
In Act 1 Scene 3 of the play, when Mr. Dussel says, "Forgive me if I haven't really expressed my gratitude to all of you. This has been such a shock to me. I'd always thought of myself as Dutch. I was born in Holland. My father was born in Holland, and my grandfather. And now ... after all these years...", he is expressing his disbelief and disorientation at being persecuted in his own homeland.
He has always identified himself as Dutch, with deep roots in the country through his ancestry. Yet, now he finds himself threatened and driven into hiding simply because of his Jewish heritage, not due to any action or belief of his own. This statement reflects the shock and displacement felt by many Dutch Jews during the Nazi occupation when they were suddenly categorized as outsiders in their own land despite their longstanding citizenship and contributions to society.