YMMV but for me, simply talking to lots of people about their lifestyles, expectations and goals helped me feel a lot better about my own.

That might sound obvious, but it's really easy to maintain a large set of relationships without ever talking about those things. Politics, science, arts, sports, etc. are so easy to fill a conversation with that it's a common pitfall to hardly ever broach the subject of who we are and what we're doing.