In a simplified example, if Investor A starts with $10,000, reinvests all dividends and capital gains, gets an average annual 10% total return, and pays 15% in taxes on the gains each year, then after 30 years he or she would have $115,583.
If Investor B starts with $10,000 in a tax-deferred account, reinvests all dividends and capital gains, gets an average 10% total return, and pays 15% in taxes on a lump sum distribution after 30 years, he or she would have $148,320, a better than 28% advantage.
In my twenties I made a number of severe financial mistakes, piling up debt, quitting a job before having good prospects for a new one, starting over in a new part of the country with no resources, and so on. Only after I had to borrow $40 from one of my brothers to get through the next week did I realize things had to change and begin to stick with a practical monetary program.
There was no secret or magic to that plan. It is contained in the suggestions I offer above. But it works and, in time, can be highly effective. If I could turn around my personal finances (and retire early), most anyone can.
And even a relative novice, as I certainly was, can learn to make good selections among equities or stock mutual funds.