Not a parent yet. But my mom did this when I was like 4 or 5, and it influenced my behavior forever. She said "I'm going to the store for a little while. You'll be home alone. Just stay down stairs and watch TV. I'm gonna lock the door. Dont come up stairs if anyone knocks. When I come home I'll wave in the basement window so you can come let me in." So I said OK! Went down stairs and watched cartoons. She then went outside, waited about 2 minutes (an eternity for a child) and then started knocking and ringing the door bell. So I just did as I was told and ignored it until she came around and waved into the basement window for me to let her in. She later told me that was her knocking on the door, and this was a test to see if I could be left home alone. Then she said she would test me like that all the time, but I wouldn't always know it. So as a kid, every time there was an opportunity to get into trouble, I would stop and think "wait... is this a test?" I never got into trouble. Lol.