Part of the beauty of travel is that you have to learn to trust random people. Note: trust does not refer to being stupid. You must always use common sense and discretion while traveling: even more so than you would back home. There are plenty of people out there looking for tourists to scam, rob, and do much worse to. If you are not yet familiar with a place, you become prime candidate #1: a lost tramp who is just itching to be parted with his/her money. Always do research prior to visiting a country. Read about crime rates, local scams, and areas that should be avoided. Don’t take a ride with a shady person, just because they offered it. It is generally bad news if someone approaches you on the street and tries to give you something.
Now that my safety PSA is out of the way, back to trusting strangers. Do it. Residents know more about a place than you do, and it would be foolish to think otherwise. Believe it or not, the majority of people in the world are friendly. If you are choosing to live life on the road, you must learn to trust strangers. Think of it this way: if a random person came over to you in the street and asked for help, how would you react? I’m guessing the answer is not: “Kidnap them and then beat them senseless.” The same goes for everyone else. If you have trust issues, now is the time to work them out.
I had a lot of trepidation when I began traveling. I’d always been a bit nervous about being a victim of crime, and it didn't help that I got scammed on my second day overseas. However, I soon realized that I couldn't walk around suspecting every passerby of malevolence. Such thinking was paranoid, and it fueled a sense of discomfort when moving about my destinations. What is the point of traveling, after all, if one doesn't interact with others?
While you should definitely travel with both eyes (and ears) open, you should also learn to notice human goodness. How can you travel in a foreign land, without relying on other people? Travel definitely teaches you to recognize good and bad character: who can be trusted, and who should be avoided. Sure, sometimes it is out of your hands. Like any adventurous lifestyle, travel has risks. Be aware of the risks before you go anywhere, but don’t let them stop you from having a blast!