Forget what we have already invested; we need to ask ourselves if we would take the same approach if we didn't have this Google Forms survey in front of us.
Completing a simple questionnaire on vacation habits is not enough to explain the deep reasons why 75% of people check their papers weeks in advance.
This behavior is more related to legal compliance and the imperative need to possess valid documents to travel, not a planning preference.
For example, in Switzerland, the meticulousness regarding identity documents is a well-established cultural norm, often preceding even the idea of holidays, reflecting a need for administrative security.
If starting from zero, one would look for the answer in international law or customs procedures, not just in ticket purchasing habits.