Of course, this mental flexibility doesn't come from mere distance, a simple change in latitude and longitude. Instead, this renaissance of creativity appears to be a side effect of difference: We need to change cultures, to experience the disorienting diversity of human traditions. The same facets of foreign travel that are so confusing (Do I tip the waiter? Where is this train taking me?) turn out to have a lasting impact, making us more creative because we're less insular.