The nice thing about blogging is that it's quick and easy. As a result, you can say things without thinking them through, as Valleywag did in this post about entrepreneurship after the age of 30. They basically looked at a handful of super successful startups, noticed that most of them were founded by people in their 20s, and then made a magic leap of the mind to say that the best time to start a business is in your 20s. Why is that wrong? Because you can never make those kinds of judgements just by looking at a sample of winners. Using winners as your sample means it is skewed from the beginning unless you are going to test your findings against a larger (and preferably random) sample to look for disconfirming evidence.
Think about this – what if 10x as many tech startups are founded by people in their 20s as by people in their 30s? Well, then all else being equal, we would expect 10x as many 20-somethings to be successful. What this means is that Valleywag's analysis doesn't prove anything without further information. The *fact* that all these super startups were founded by 20-somethings may be primarily a result of significantly more 20 somethings entering the startup scene. I'm not saying it is, I'm simply saying that we don't know from Valleywag's chart.
Blogs dealing with startups and entrepreneurship seem to be particularly vulnerable to this "find the secret sauce" kind of thinking. Everyone wants to be a successful entrepreneur just like everyone wants to win the lottery. And just like the lottery, there is no "secret sauce." Successful entrepreneurs have all kinds of personality traits and come from all across the board. Hard work, creativity, and all that other stuff are necessary, but not sufficient, for entrepreneurial success. Luck and timing play a role too.
My advice for entrepreneurs is to stop looking for that magic bullet and start doing stuff. It's the Mark Cuban theory – keep trying stuff until you figure out something that works. Don't worry about whether you are too old, too young, too short, too ugly, or whatever else it is that's holding you back. You are going to fail a bunch of times anyway. May as well get it out of your system early.