I actually agree with you on this one.

We have at best a few hundred years of data to support trading market behavior. And the data actually does not support the parent if you go back in time, instead of simply cherry-picking growth in the 20th and 21st century. Stock growth during the 19th century was not really that great in comparison to the 20th century (http://ritholtz.com/wp-content/uploads/2011/01/Real_Stock_Growth_Log.png)

Let's also not forget that even the United States, and most of the western world ALSO does not have a very lengthy track record of stability. We had a world war less than a century ago. The odds are extremely good that some type of cataclysm or collapse will happen in the 21st century, the same as the 20th.

I guess that brings me to the point that while making long plays on equities isn't a bad thing to spend some of your free cash on, it would be a pretty dumb idea to bet the farm on them. I would diversify in Real Estate, personal career development/diversification, AND perhaps a reasonable share of long-term investments.