Quote from HolyGrail:
2000 was a true bubble. This type of bubble will typically happen only once in a lifetime. The reason for this is quite simple. Memory. People that were around the markets and got burned will never allow themselves to be put into the same position again. 2000 was actually very easy to see coming because fewer and fewer stocks kept the indexes going higher.
Very true. I remember my dad telling me about the depression and how there just wasn't any opportunity. He graduated from university in 1927 and ended up selling magazine subscriptions door to door. The depression definitely colored his perspective on investing, which he didn't get into until the late 1960's. There were thousands like him. For a generation or more the stock market was just too "risky" for most.