Fillable form data disappears after saving

There was a time, many years ago, when it made sense to do this. I even advocated the use of a particular script for resetting the fields when the form was opened that I still see in use today. The reason for doing this was to reset forms that are used in a browser. At the time, form data from the previous use of the form was automatically reloaded from a temporary FDF (Forms Data Format) file that Acrobat/Reader generated. This presented a security problem, and the only thing to do was reset the form when it was loaded. This was before Reader was able to save a filled-in form, so it made sense. Since that time, Adobe removed this automatic form data loading feature, so there is no longer a security problem and it no longer makes sense to reset the form upon loading in most cases. You still see some people wanting to automatically reset the form each time it's used, but it's unusual these days.