I like the open source editor Notepad++, but it has one default setting that drives me crazy: When you close it, it remembers the current “session”. This means that when it gets started the next time, it will re-open all the files you had open when you closed it the last time.
The setting for turning off that behavior is hidden somewhere in the complex Preferences dialog and I keep forgetting where.
So, here you go, future me: It’s on the “Backup” page: