Comment by scotty79

> Even if you think you know something, you are, at best, still being random

Technically true. But somehow in practice you are random in worse ways. Psychology of most people makes them generate very bad randomness.

But you are right. What I said is just good first approximation. Sometimes you can do better. For example listening to most popular financial influencers and doing exactly opposite of what they recommend gives slightly better returns (it was researched). I don't quite remember if better than fully random though or just better than following their advice.