Well, let's talk about why you feel this comes from childhood. How was your childhood? Were you abused in any way? How were parents? Only child? It would help you to explain this comment, which I think is important.
"Selfish" is a term used by bitter people who want to paint a vast dark picture of your situation. Nothing wrong with being assertive about what you want, just don't press the issue too hard.
You seem to have more needs than others. Maybe your childhood was poor with love and especially material objects or even food. But the main thing for you is to learn to love yourself. That alone should fill you up. And other people will see it.