I’ll go first. Mine is the instant knockout drug. Like Dexter’s intramuscular injection that causes someone to immediately lose consciousness. Or in the movie Split where there’s the aerosol spray in your face that makes you instantly unconscious. Or pretty much any time someone uses chloroform.
When there’s a breakfast table full of food but the protagonist is running late so they only take a bite of toast and then leaves.
The overloaded breakfast table is a trope so tired they were parodying it 30 years ago.
https://youtu.be/R-Uq20BUFOo
https://youtu.be/aJ9xAhsh0H0
Yes, or people leaving a bar without finishing their drink. Like full glasses in front of them and they both stand up and leave without mentioning it.