For me, the rule that says it is not scary to be sure of something, but it is scary to be overconfident, always holds. There is a big difference between these two feelings. Yes, we know that we can win by understanding a few things and knowing some obvious things, but our overconfidence can let us down, because in addition to our knowledge, there are surprises that are likely. And then we can bitterly regret if we bet on an amount that is very significant for us.