A lot of good points made. 

I'd direct members to a post i came across a few years back which discussed the inevitability of short term underperformance within longer periods opf outperformance:

Every long-term investment strategy – even the most successful strategy – will experience periods of poor performance.

This is both desirable and necessary. Periods of poor performance relative to the market create a fresh crop of opportunities; but only for those who are patient and disciplined enough to maintain a long-term perspective.

Investors that would like to try to beat the market need to come to terms with this fact. Otherwise, they will be much better off investing in an index fund.

The full post can be read here -- i think it addresses the question really well.