There's an HBR article by Tony Schwartz saying that Happiness is Overrated. This is misguided, in my opinion, especially after reading Barbara Fredrickson's book on Positiivity and Jonathan Haidt's book on the Happiness Hypothesis. Though I agree that the bliss of ignorance or of denying the truth is dangerous--that's not the same thing as happiness. I'd also agree to focus on engagement, rather than happiness--since that's what Thiagi said at the Agile Games Conference this year: it's all about engagement. We're affected even more by negative experiences than positive ones (Fredrickson); but as scrum masters/coaches/trainers we don't want to be violent (Albiez, private conversation). As I understand it now, Sharon Bowman helps gives us many opportunities to walk around the room and check to see if people are getting it, to assess their engagement, and therefore keep them learning.
Maybe the title of "Happiness is Overrated" is just a headline intended to capture readers. Frederickson talks about this, shows how positivity opens & broadens our minds to more creativity, more motivation, etc. As Schwartz says in this article, we need to see reality for it is--AND as Haidt says, we need to be resilient to the bad news, to spin challenge into opportunity.
IMHO, paying attention to our energy, living to the fullest level of engagement, is what we want to coach our teams to do. Often this is a happy place... or as the gamers say, it's "serious play". Too much negativity and we get frustrated, we fall apart. Too much challenge and it's not fun. Engagement = Fun.