"When you're at a bus or train stop at night, with nobody else around, and you hear young guys talking where you know they go in your direction, quickly disappear before you get in their sight.
They may be harmless, but as long as the probability they want to start [things] as soon as they notice you is there, don't take a risk. Learned that the hard way several times. "
Switzerland?
Most of Europe except some corners in Frankfurt, London or Paris.
Life is easy if your brain only works in black and white!