One cannot simply take survey results as irrefutable evidence to explain why people check their ID papers in advance or at the last minute. It is an observation, not a direct causal explanation of behavior related to preparatory stress. If we had not already invested time in this 78-response survey, we would treat these figures with much more caution before claiming they represent all travelers. For example, a person in Germany expects a strict bureaucracy and would check their papers well in advance, which is not necessarily related to stress. We should ask ourselves: Would we make this investment again if we had to do it over, just for this conclusion?