A lot of times it is not necessarily knowledge losing traders lack, it's their money management skills. Risk management should be a traders #1 concern at all times. Over-leveraging and maximizing risk exposure WILL catch up to a trader that is not careful at some point.
However, there are plenty of 'traders' who simply figured out how a candlestick chart works and think they're going to make millions.
Spending time reading charts and watching price action is mandatory for becoming a successful trader.