There isn't a thing wrong with engaging strangers in conversation. Some can be very interesting. Isn't there a line about a stranger being a friend you haven't met yet? How will you get to know anyone if you don't speak to them?

Next time keep them on you. If you travel that's just logic. All important items you keep as close to your person as you can. Including those things that can give you an easy escape in social and stressful situations.

You're very welcome.