Not being selfish and being selfless are too far away from each other than the usual understanding of humans.
A typical example :- When Cristiano Ronaldo looks at his match stats and compares it with Lionel Messi‘s, he runs and hides behind his cabin in the Real Madrid player locker room. Cristiano Ronaldo may become unselfish, but never selfless like Lionel Messi.
Prerequisite knowledge requirements to understand this comparison :
Cristiano Ronaldo is proud,arrogant, selfish-on-the-pitch, womanizer off it.
Lionel Messi is humble,selfless-on-the-pitch, kind and generous off it. So Lionel Messi will be in bold for the rest of texts for the rest my life