In Remains of the Day, what differences are there between Stevens in the first and last chapters? Is it me or has he not changed much at all ?
I think the main difference between Stevens at the beginning and end of the book is that, in reflecting on his past, he is aware that Lord Darlington, to whom he devoted his life, was not the great person that Stevens believed he was. I also think you are right, however, in concluding that Stevens, despite this realization, has not changed much at all.
As a butler, Stevens believes that the best thing he can do in life is to "serve a great man who does important things" (see enotes link below). Darlington was that man for him, and Stevens, who served him unquestioningly, feels that from his own perspective at least, he has done his job well. Although he now realizes that Darlington was a Nazi sympathizer and pawn, he concludes that "the hard reality is, surely, that for the likes of you and I, there is little choice other than to leave our fate, ultimately, in the hands of those great gentlemen at the hub of this world who employ our services" (Day 6 - Evening). Even though he now sees that Darlington's leadership was not always good, Stevens does not fault himself for having followed him. As Stevens admits early in the book, he has "a reluctance to change too much of the old ways" (Prologue July 1956). For Stevens, to efface himself in service of the "great men" remains his ultimate and unchanging standard.