I'm saying this out of what i've learnt from other people, not sure if it's actually the case. I would also say there's much more to becoming a millionaire than what your told, if you could just read loads of investment, finance books, brian tracy etc. Many people would become millionaires, in theory they say what should work, but think about how many people also followed their advice, yet aren't rich at all.
You will probably never become a millionaire just by doing a job, even the top jobs won't pay that much after tax, you have outgoings like your house bills etc, but you have to learn how to cut expenses (this is the easy part) right down so that your nearly spending nothing, most can't actually do this as they lack discipline, most would still waste their money on crap, which is only the first part of becoming rich.
Learn how to invest, if you have good stocks/bonds, you compound the interest that you save, so for example a 9% interest rate would double your money in 8 years (72/9 = 8 - rule of 72), I think before you learn how to analyze a company properly you would need to run a business first. I for now am learning how to invest, have read Benjamin Graham's "The Intelligent Investor", and other books, i'm getting my head around it, but need to actually put in practice what i've learnt. It's not such a great way of making money when you don't have much as money makes money, but once you have a good amount, you will get bigger returns, think about time, spending years learning to invest just to put down a few grand is pointless, when your young you learn the principles before you get older to actually deal with big amounts, consider time.
You don't become rich fast, complete load of rubbish, it takes years to accumulate, think from now you were to put in £20,000 into an investment with a 9% return, 30 years later you would have £280,000 if that's calculated right. So more money you have to begin with, the more money you can make.
But I would say that you do actually need to be born somewhat rich to actually get rich, you could get a good job without being in a good position (like me), but after a few years of saving and learning how to invest, you have a bit of money to put down, then go for it, the rich don't put their money in 2% ISA accounts, they know what to do with their money properly, they do extensive research into investment, most that invest will only get an average return, it takes time to learn this stuff in depth.
I think it's much harder than what you are thinking, I used to think like that at a young age. People are very optimistic about being rich, then slowly the reality starts to hit them, but that's not to say you will never become rich, because you probably could if you really wanted to, it will be harder than you think though, and you have to realize many people think like this, many people even take millionaire's advice, but never become rich, you might learn someone elses path, but that doesn't mean their path will be open for you, it depends on many factors, it's delusional to think that it's solely down to you.
And also, what would you do when becoming a millionaire? Many people want money, then have no clue what to do with it when they get it, most of the super rich just spend their money on **** as they have no clue what they actually want with the money. Before you even become a millionaire you will think you have excessive amounts of money to even want any more.