Both numbers can easily be fucked up too.
5 million, if you are in your 20s, properly invested and saved to be used slowly throughout your life - best established as an automatic self-payment (grab lump sum, make better investment decisions than the lottery's annual-payment option, and create some kind of trickle payout like a retirement/pension payout)... and yes, you could quit, retire, and live comfortably for life.
If very intelligent with financials (or you hire a financial/investment genius), it could make it easy to provide everything for children too. Depending on how grand your ideas are, of course.
That kind of money, that early in life, cannot afford mansions and extravagant purchases. It is not the amount that affords multiple supercars (or multiple six-figure vehicles in general) or multiple homes of similar stature.
A modest, upper-middle lifestyle is possible with such a payout. But in practice, you'd have to be more reserved that that. Such a payout is not even in the range of lifetime savings that smart 6-figure earners can achieve (the ones who have been that way for the majority of their adult life and are currently around the retirement age at this very moment), so you can't start living like one of those earners, at least, you can't jump to their stature and continue to live like them. Gradual versus instant for investment/purchasing purposes produce vastly different results in the books in ways many people don't think about if they don't properly educate themselves.
And on the other end, someone suddenly receiving Billions can easily land in the gutter if they make bad financial decisions. Just because you receive such money does not mean you can suddenly live like the Richard Bransons (financially intelligent and eccentric) or Warren Buffets (beyond mindblowingly rich, also financially intelligent).
To make any kind of sudden windfalls work, you have to be smart with your money. When you are still early in your life, you have to be financially savvy to make any kind of lottery winnings provide an immediate retirement. Most people get too dumbfounded when it appears they can buy everything they want right now. Very few stop and plan how much a lifetime actually costs in the first place; it won't be an automatic part of an income-based budget [without a planned banking/investment strategy] and thus you have to start with at least a rough estimate of how much you must set aside to provide for all financial costs of the future. After that, you are left with the true "windfall" that still must cover a lifetime of emergencies, personal purchases and expenses ("treating yourself well"), and covering any kind of large investments.
