Question

Many new ideas were recorded in Upanishads can you list some of them

Answer 1

many of them wanted to know life after death and others wanted to know why sacrifices should be performed.

Answer 2

Answer:

Many of these ideas have been recorded in the Upanishads in the form of conversation between teachers and students mostly Brahmanas,rajas,and sometime women. however, besides a few exceptions, people of lower status mostly did not take part in these discussions.