I think so too, but it's not always the case. It's not always possible for some people to be happy in their current situation, example being a bullied kid in a high school or a woman dealing with a toxic husband.
About wealth though, @apolymask and I had a discussion about something similar a while ago and agreed that it's possible to be happy with your current state and still desire for more. It's to keep a balance between gratitude and longing for better.
About the quote formatting, all you have to do is put a ">" before starting the sentence/quote.