[brk]

If you spend a disproportionate amount of time on HN, you can easily be led to believe the "typical" startup founder is an early-20's hoodie-wearing recent grad.

The reality is that starting a company in your 30's is probably the most common first-time startup founder age-range. It partly depends on market and business idea though. I wouldn't want to be a 38 year old guy pitching an idea for a social viral bar-games scoring app. But, for the sorts of ideas that tend to require bigger money and a more refined approach, I think I'd rather pitch that at 35 vs. 25 in today's market space.

Also think about hiring good talent in general (assuming you want to build a "business" and not an "app"), many people would rather work for an experienced CEO in their 30's, but the mid/early 20's set seems to have an edge on very refined "apps" (be it Android/iOS or small webapp) type of businesses, where 4 or 6 people may be able to makeup the core of the company for a significant amount of time.

Just my opinion, as a late-30's guy who has been rolling through various startups (my own and working for others) for about 18 years. YMMV.