People get to be either selfish (bad) or selfless (mostly good).
Considering only the self: Selfish.
Considering only the other: Selfless.
Now consider that we exist together in a context, and in relationship.
I want to consider the self, the other, and the context.
And I want to be self-full when I do that.
"You are so full of yourself".
That is a compliment.
You mean that I am my own self, full of awareness of who I am and what I need?
When everyone in a moment and context together does this, life feels balanced to me. And safe.