How fun to think only of your interests for a while and focus completely on blending in to a foreign culture, or at least being able to observe it quietly/thoughtfully. I loved keeping my travel journal on the train. I had a thing for ancient Rome at the time, so whether I went to Spain or Hungary, I looked for the Roman ruins. I learned a lot; no one was rushing me. I must have a surprisingly good sense of direction when I need it, because I never got lost (even without a smartphone!) No one laughed at my attempts at the local language.
I never felt unsafe traveling alone in Europe or parts of U.S. (OK, D.C. can be scary). Mainly, I got up early to maximize daylight and museum time, then went to sleep early, so I wasn’t out in the dark much. When I walked in strange places, I was aware—not distracted by guidebooks (I researched ahead of time) or ear buds.