Hiding and then showing objects turns on layers that were previously off
<omitted statement expressing how deeply disappointed I am in Adobe Illustrator now, an application I've been using since 1990>
When working on files with dieline layers, we sometimes turn off portions of those layers that include unnecessary information. Lately, I've discovered that if I decide to hide an object on a layer to perform a change, and then show that object again, all the sublayers that were previously turned off are spontaneously revealed again.

