What's the difference in Serving Self vs Serving Agency? (Knight of Heart and Life)

If you’re serving /yourself/, not much, but if you’re serving others, they’re completely different things. Serving someone else’s self just means you’re aiding them. Serving someone Agency is specifically allowing them to do what they want to do. Paving the road in a way. Even when it’s serving yourself, I feel there’s different ways that could work.