Against Walmart I can use judo business strategy. 20 something's use judo against each other.
Sorry, but I have to disagree. Capital, economies of scale, strong management, etc. -- these things are very real advantages and matter to the viability of a business. I'm not saying it's impossible to compete with entrenched businesses, but don't think for a second they're not able to compete right back because they don't have "judo business strategy."
http://judoinfo.com/pdf/business.pdf
Judo strategy is when you go up against a larger opponent and use their size to your advantage. It's an easy term to google.
Judo strategy is employed most famously when you price to capture a fraction of the market such that their cost to win those customers back by lowering their prices would have a higher cannibalization cost to existing customers than the benefit of getting the lost customers back. Price is just one of the ways to use a judo strategy, but it is the easiest to understand.
I'm telling you that 20 year olds often have zero opportunity cost, zero holding cost, and zero living cost. Because they exist in a "pre-adult" state, they are scary to compete against because they often can act irrationally for long periods of time with no repercussions.
If there is an opportunity, I'd rather go up against a large multinational company who will almost always act rationally but inefficiently than a field of likely to be irrational opponents.