Well, it is important to be calm and confident but it doesnt mean that you should not think about each step before actually making it. The secret of success is in the balance.
If that excessive confidence will make you not to accept your mistakes, then that should be wrong.
When trading, this is a big mind games, we can't just assume without basis and based on my observation, those people who are humble are willing to learn and improve and when they do that, they'll likely be successful in what they do.
Life of a trader is hard, adjustment should be done from time to time as the market is not moving stable, therefore its hard to predict what will happen next, but if you open for all the possibilities, for sure, you can make more good predictions than wrong.