One of my strengths is I have a pretty even temperament. I don't get too high when it's high and I don't get too low when it's low. And what I found during the course of the presidency, and I suppose this is true in life, is that investments and work that you make back here sometimes take a little longer than the 24-hour news cycle to bear fruit.

I confess to wincing every so often at a poorly chosen word, a mangled sentence, an expression of emotion that seems indulgent or overly practiced. I have the urge to cut the book by fifty pages or so, possessed as I am with a keener appreciation for brevity.

Our intelligence agencies will continue to gather information about the intentions of governments - as opposed to ordinary citizens - around the world, in the same way that the intelligence services of every other nation does. We will not apologize simply because our services may be more effective.

My biggest frustration so far is the fact that this society has not been willing to take some basic steps to keep guns out of the hands of people who can do just unbelievable damage. We're the only developed country on Earth where this happens. ... And it happens once a week. And it's a one-day story. ... The country has to do some soul-searching on this.

I think that there's gonna be a lot of work to do in order to consolidate the transformations that I was interested in.

The issue of climate change is one that we ignore at our own peril

So don't get cynical. Cynicism didn't put a man on the moon. Cynicism has never won a war, or cured a disease, or built a business, or fed a young mind. Cynicism is a choice. And hope will always be a better choice.