We are in the same class of 1999, but I learned almost totally different lessons:
1)长期投资(不是buy and hold,而是要一直在市场里) - agree on this;
2)Never 分散投资, only focus on the 1-2 sectors/industries I feel I understand;
3)Never focus on section rotation,because I don't know where to rotate outside my comfortable zone;
4)Never do DCA(假设市场总是曲折向上,因为经济规模不断扩大及货币贬值), I do raise/lower my cash level to manage Macro risks;
5)少炒指数,多买个股 - because my goal is to outperform market. The downside is I could have big swings, but I get used to them and feel comfortable,most of time.
差不多又是十年过去了,可以安慰的是这十年效果尚可...so you and me make two different cases to demonstrate 'there are more than one ways to skin the cat'...