The best road to discover the truth is falsification of refutable propositions (Popper). Your central thesis is irrefutable, because it relates two undefined, vague concepts: socialism and selfishness. In so far as we assume that we know what you mean by socialism and by selfishness, your proposition is impossible to falsify (or verify), because you haven’t measured ‘socialism’ or ‘selfishness’, nor their causal relationship, in other words, you do not offer any factual proof of your proposition, nor did you define the precise conditions under which this assumed relation could exist.
What you show is verificationism. You make a proposition and ‘prove’ it by offering one anecdotal example, that can easily be falsified by practice.
Apart from this I have to admire your attempt to leave your bubble and venture into the world of the opposite ideas. It could help though, to travel to Western Europe (the continent) and observe some societies over there. You will see an interesting mix of conservative and progressive policies, implemented by coalitions of the left, the center and the right. Compare the quality and accessability of welfare system, the health system, the educational system, the judicial system and the political programmes of the many political parties, with the systems produced by the ultra capitalist system in the USA. Travel with high quality public transport or on a safe web of highways. Enjoy the miriad cultural institutions and old cities, maintained with public money. After that, I bet you want to stay and never get back. If you are selfish enough.