You won't get a single body of thought among either group, and you'll have trouble defining those groups. What is old? What is young?
Among my personal contacts, both young and old, it's not often a topic of conversation. I'd say that most people, in their day to day lives, don't give it a lot of thought. Young people tend to be more idealistic but that wears off as they run into reality. Of all the old people I know, only one has stated directly, "I don't care. I won't be here." It's a lousy attitude from an unpleasant old man and I don't think he's by any means typical.
It's a good question but I don't think there's an answer.
Malizz 