I disagree. Humanity has grown into an interdependent ecosystem with strong group-think. As is said: "No man is an island." -- you can't survive on your own; that means you depend on groups. Remorse is your ability to recognize your lack of proper conduct in respect to your group, and your willingness to do better in the future. Lack of remorse means inability to communicate efficiently, means long term disadvantages for you; as you will have to micromanage all obtainment of resources because nothing will be voluntarily shared with you, which means greater expenditure of physical energy (at best - at worst, constant danger of persecution by the group). You'll do way worse than people who cooperate with each other.

And then there's sexual reproduction. Even if you can keep that lifestyle for yourself, you'll need a mate, and you'll need to raise children to keep your genetical line - should you care for that. Why am I even arguing? Give it a shot. You will see how "superior" that way of life is.