The Money Wizard clearly figured something out — and he shares everything he's learned so far on his personal blog — but just how much sacrifice does it take to set himself up for such an early retirement? How much of his salary does he direct towards savings?

At age 22, "The Money Wizard," who goes by the pen name Sean and asks to remain anonymous, decided to fast-track his retirement.

When he landed a financial analyst position in Denver at age 23, he immediately started setting aside 35% to 40% of his $50,000 entry-level salary, he tells CNBC.

After relocating to Minneapolis a year ago and moving in with his girlfriend, with whom he splits various fixed costs, and thanks in part to the fact that he doesn't have student loans to pay, he's able to set aside more than 60% of his now $70,000 salary. With this savings rate, he expects to have at least $750,000 in the bank by 37.

While 60% seems remarkably high — especially considering the savings habits of the typical American — the Money Wizard claims it's more than possible if you keep your fixed costs in check and are conscious of your spending habits.

"Design your life so that the fixed costs are as low as possible," Sean tells CNBC. "Pass on the really expensive apartment. Pass on the status-symbol car. Question the things you spend your money on and make sure the things you're purchasing are actually making you happier."

Resist the urge to keep up with the Joneses, he encourages: "Ignoring the expectations of others is probably the most important obstacle in the path to uncommon wealth.

"Do you want to reach complete financial freedom, or do you want to impress strangers who plan on slaving away in middle management for the next 40 years? Freedom to do whatever you want when you want, or a fancy car that might make a stranger look twice?"

Today, the Money Wizard lives comfortably on less than $25,000 a year — it's doable, he assures, with the right mindset.