The idea that your success matters to me may sound a bit odd at first; it certainly seemed odd to me when the thought first arose.
Why should it matter at all to someone if someone else (a stranger) is doing well, is happy, and thriving? I think because we aren’t truly strangers.
Our society, at one time condoned the practice of slavery. No culture has ever endured with the practice slavery in effect. The degradation of a human being by another is so repellent and negative that it eventually brings the society down into a state of chaos (The U.S. Civil War) or dissolution (The Soviet Union).
Substitute the Slave Master or the Politburo for a modern day equivalent and the result is always the same. A government, for instance which encourages non-production in return for handouts (to buy votes) is a “slave master”. A government that encourages fear and punishment of productive companies who hire and promote individuals is a “slave master”.
Your success and creativity matter because as long as you are productive and happy and fulfilled, you cannot be a slave, nor encourage the slavery of others.