The effects of fear on one’s behavior are obvious, limiting one to the point of complete immobility. If you can’t execute your trades properly, even when you perceive the most perfect opportunity, it is because you have not released yourself from the pain contained in the memories of past trading experiences and because you still don’t trust yourself to act appropriately in any given set of conditions. If you did, there would be no fear or immobility.
– Mark Douglas, The Disciplined Trader