My optimism and confidence come not from feeling I'm luckier than other mortals, and they sure don't come from visualizing victory. They're the result of a lifetime spent visualizing defeat and figuring out how to prevent it. Like most astronauts, I'm pretty sure that I can deal with what life throws at me because I've thought about what to do if things go wrong, as well as right. That's the power of negative thinking.

Decide in your heart of hearts what really excites and challenges you, and start moving your life in that direction. Every decision you make, from what you eat to what you do with your time tonight, turns you into who you are tomorrow, and the day after that. Look at who you want to be, and start sculpting yourself into that person. You may not get exactly where you thought you'd be, but you will be doing things that suit you in a profession you believe in. Don't let life randomly kick you into the adult you don't want to become.

I'm really looking forward to it, if you can imagine floating weightless, watching the world pour by through the big bay window of the space station playing a guitar; just a tremendous place to think about where we are in history.

If you haven't learned to ride a bike by the time your peer group has, then suddenly it's an embarrassment and you'll avoid opportunities where you're expected to ride a bike. And then it starts shaping your behaviour. Reading is much subtler, but much more destructive if you have not - for whatever reason - learned to read by the time you should.

My favourite city for nightlife is Toronto, as it has such a multicultural feel, with so many different restaurants and theatres.

The Moon has given us months, tides and a destination that ever-beckons. It's time we build a rocket and go to stay.

Sweat the small stuff. Without letting anyone see you sweat.