question about the marauders

so i just finished prisoner of azkaban and i really enjoyed it i heard people said that things were cut one of them being quuite big where people talking about the marauders which are peter lupin james and sirius right? i dont know if im crazy but i swear i never saw them talking about it in the old shak or whatever the english name is since im reading in dutch or atleast not talking that extyensivly about the background in the movies like i swear they only talked like 1 minuete about that shit in the movie is that correct or am i just stupid?

and second thing i just thought about while making this is when harry and dumbledore are alone in lupins office he says that harrys father could turn into a deer or atleast thats what they translated it into dutch and thats why his patrnus looks like a deer but i swear in the movie dumbledore says harrys fathers patronus was a deer and thats why his also is until reading the book i never noticed a mention of harrrys father being able to turn into a animal like lupin sirius and peter

so again i maybe just forgot it but am i right or just bad memory?