How could I become a millionaire by age 23 by inventing? (I'm currently aged 20) Where, and how do I start?

Firstly, I would propose that ideas (and, their patents thereof) belong in the receptacle offered by the device in the carefully selected image, above … … it’s all about execution. And, as we know; that’s 99% perspiration Given that, it seems you have quite a few paths available, to take Useless Idea # n to Highly Profitable Business # 1, but I think I can summarize them into just two: 1. As suggests, become an idea/licensing machine: churn them out, begin the patent process, licence off … next idea! 2. Pick the one idea that you feel has the most commercial promise, fail fast (which means assess the market quickly by trying to get sales and feedback … even before the product is ready), continue with that idea OR shelve and move onto the next.

I think this is feasible, and the route I'd take is licensing. You "simply" invent a new product or improvement to an existing one that solves a problem people will pay to have solved, or which provides a clear value above what exists already. You then grab a cheap provisional patent on the concept and shop it around to the companies that would be your competitors if you started trying to turn your idea into a new startup. You grant them rights to use your technique or sell your invention under their label, and they give you 2-10% of the wholesale price of each sale. Believe it or not, companies really do buy inventions from outsiders all the time, because they don't always have the resources to invent in-house. But - you need to be inventing the right thing. There's a book called "One Simple Idea" by Stephen Key about how to do this, and although it's a bit over-simplified (like my explanation above), it's a achievable way to make big money in reasonable time.

Starting your own business is the best way to become wealthy, not just Bill Gates wealthy but also for achieving moderate wealth, because with a good idea and leverage you can dramatically increase your earning power. That having been said, it is also very risky, with many new businesses ending in failure. At your age and based on your self description (no strong professed interest for trading financial instruments) starting your own business is probably the best way to generate wealth and you are young enough to recover from the risk fairly easily if it doesn't work out by 23. First I would try and figure out what you want to sell (it sounds like you are interested in product design) - which begs the question of what problem you are trying to solve, it is hard to sell something that doesn't solve a need or fulfill someone's desire. After spending sometime thinking about that, I would take some time and read some books on entrepreneurship -  while some people mock him, I find the four hour work week by Tim Ferris is one of the most practical books on starting your own company. I would also recommend the Lean Start-up by Eric Ries. Try out some of the things they suggest and see if you can refine your business idea. Then get out there and try and see if you can sell something, getting something out there fast and getting feedback on it is very helpful for making a business succeed. Keep reading blogs, refine your idea, and try and make it better and maybe you will become one of the lucky few who strikes it rich, and if not rich maybe at least you will get independence and some control over your own life. At the very worst, you'll have a good learning experience on initiative, perseverance and trying to do something very very hard. Good luck

Keep your eyes open for small problems around you , that people just become complacent to. If a problem clicks then think of solutions, talk to people , gather ideas. For prototyping, get involved in local makerspaces. You'll get lots of great resources that way. Also, get familar on business side of things. I learn a lot from watching Shark Tank (TV program) - you'll see the difference between product and business.. and you don't just need a greta product, you need to build a great business. Overall just get started, there is no magic formula. Pick up the first problem you can see and get started.. things will build over a period of time.

Inventing is only a tiny piece of the equation. You will have not only invent something for which there is a market but also take it to the market. If nobody knows your wonderful invention and does not buy it, what is the point? If you got something great, China will probably copy it before you know and undercut you.   Getting where you are from now, 3 years is probably overly optimistic. I would say that it would be great if you are past the break-even point at that time.