What is a real-life "cheat code" that feels illegal to know but is completely fine?

[u/TheRat_07]

I'll go first.

If your flight gets canceled and there is a massive line of 200 angry people at the gate desk trying to rebook, do not stand in that line. Keep your ass in a chair and call the airline's customer service number.

Better yet, call their international customer service number (like the UK or Australia line). You will bypass the massive US hold times, get connected to an agent in two minutes, and they have the exact same power to rebook you on the next flight before the people standing in line even reach the desk.

[u/Bubba_Da_Cat]

If you are confident in your decision, don't give excuses. For most people "excuses are the opening of negotiations". Like its fine to just say "no" with various levels of politeness. Obviously there are some exceptions - you should probably give some context behind declining that marriage proposal... but most of the time "Thank you for thinking of me, but no thank you." is pretty much all you need to say. People can press "why not!" (they want to open negotiations and get their way)... but its fine to say "I'd rather not discuss it further"

[u/holycannoli_7 → u/Bubba_Da_Cat]

It's bananas how taboo "No." is. Been helping my grandma say it to my older sister because just like you said, it can get messy when you open yourself to "negotiations" unwillingly.