It can be very different for each person but, you must step out of the comfort zone that you build around yourself. Travelling is one the most highly recommended things to do to open up your mind, but sometimes that isn’t enough. Find that one thought that makes your heart race, that makes you feel nervous, and make a b-line towards it.
Skydiving may be that something for you. If you watched that whole video, I’m Sorry. Watching other people skydive is as almost as fun as reading someones blog that makes you feel like they are better that you. If you are still pissed about the video, then you missed the point. It is symbolic to the notion that what you perceive as so uncomfortable really is not. When a thought makes your heart race, it makes you feel alive. Life is about living, let whatever comes afterwards feel like dying.