I can understand his frustration but how relaxed you are probably depends on the performance of your portfolio.

I am very much in favour of a diversified one, meaning that I do not put all my eggs into one basket. True CMM still makes up a whopping 21% of my junior mining portfolio, but this used to be much more. In the period when CMM went down from 80c+ to 40c, other stocks have done extremely well, such as BTO & GNH. This gives some peace of mind. My personal view is that I should never own a stock that makes up more than 25% of my portfolio. It's just too risky & stressful. Some may argue 25% is even on the high side.