I guarantee if you walk into 100 spider webs, you will have changed your fundamental human behavior. And you can apply this to anything, And figure out a way to reprogram yourself, to change your primal fear.

Other anatomical changes associated with long-duration space flight are definitely negative: the immune system weakens, the heart shrinks because it doesn't have to strain against gravity, eyesight tends to degrade, sometimes markedly (no one's exactly sure why yet). The spine lengthens as the little sacs of fluid between the vertebrae expand, and bone mass decreases as the body sheds calcium. Without gravity, we don't need muscle and bone mass to support our own weight, which is what makes life in space so much fun but also so inherently bad for the human body, long-term.

There is a sunrise or a sunset from space every 92 minutes so there is an incredible amount of beauty to see from up there.

It’s not enough to shelve your own competitive streak. You have to try, consciously, to help others succeed.

Almost everything worthwhile carries with it some sort of risk, whether it's starting a new business, whether it's leaving home, whether it's getting married, or whether it's flying in space.

It's good to have a fear of heights. I mean, it's kind of crazy not to because if you just lean out a little bit and there's a gust of wind or somebody bumps you or something and you fall, you're splat.

I've been lucky enough to fly to space twice.