I'm sure I'm about to be ridiculed - but I have one more suggestion. Twice, in the last year or so, I have left both our outer and inner main entry doors unlocked. It's a geezer thing I guess ... . So - here's what I have done - I have set a daily reminder on my iPhone calendar to "Check Doors" at 9PM - with reminders 15 and 30-min before. In my defense, if I get busy with life ... sometimes I forget the basics!