Life is full of opportunities to learn. Some experiences are are perceived riskier than others. 

Sir Edmund Hillary became the first man to summit Mount Everest (with Tibetan sherpa Tenzin Norgay).  However, not everyone would wish to accompany such a perilous expedition to climb a dangerous mountain.  If you did join the team, and decided turn back, could you bring yourself to give up th mission and do that? Would you take the risks involved in retracing your steps in uncertain weather?

Consider anyone who decides to backpack though a foreign country, or more challenging still, to backback through many unfamiliar countries.  To take the risk of stepping outside what you know can be a scary thing for many people. You would need to find maps, navigate through places you've never been, do things as simple as find food, a toilet, a safe place to sleep, when you don't necesarily speak the local language, dress like the local people, or share their perspective on life or the world. This would require courage and the willingness to learn new things.

Before you travel anywhere, you would likely evaluate risks. Should you stay where you are or should you go discover someplace new? If you do decide to take risks to step outside your comfort zone, you would likely consider things like potential threats to your health and safety.  Could you even qualify for health insurance? Would you wish to have any? Could you afford the trip? Do you have responsibilities that you could afford and you would be willing to leave behind?  Some of us would choose not to turn our backs on mortgages, family and other priorities.

What kinds of incentives would motivate you to re-think the life you know and consider it something you could leave, at least for a time? Some people would abandon theri lives at a moment's notice with few belongings.  Other people require extensive planning in advance and would take much luggage.  The nature of the travel destination and purpose of your trip would influence what you think you would need.

Then again, it's possible that visiting foreign places may not even appeal to you. You may find it risky to live where you do everyday.  The idea of getting into a car and driving somewhere involves a certain risk. 

Risk is relative to what we know, to what we don't know, and to what we have the inclination to learn.