If you could plant a single thought in the minds of everyone on Earth simultaneously, what thought would you choose to share?

I've been saying for a while that if I could, I'd increase baseline human empathy by 50% or enough to raise its minimum value to current baseline if they have less than 50% of baseline to start with, all up to a maximum of triple baseline levels. Enough to make the world a much better place, but not enough to make millions of people mentally ill or otherwise do more harm than good.

I'd consider anyone suffering negative side effects to be acceptable casualties.