I find this thread pretty amusing because I'm ~40, have two kids, have made good money over the years in a good field (not consulting) and there's just no way I'm retiring now, and I have more money "saved" (in my world a lot is tied up in carry) than some of the examples above. Like @CorpFinHopeful and @Tred1 have said basically, life is expensive and much more expensive than you think when you're either in school still or young and don't have kids and all of the costs that come with them.
A couple hundred grand a year sounds like a lot to a 21 year old still in school, but it's just not that much money after taxes unless you're living in Iowa. Even if you don't go crazy and buy multi-million dollar homes or insane cars, a nicer but basic house near a major city is easily $1MM. A million dollar home sounds like it's going to be a mansion but that's a 4-5 bed in a somewhat closer suburb to a major city, especially in the northeast or California (SF/LA).
If you live near NYC in Jersey or CT, property taxes are going to top $30k p.a. on that house and that's not in Greenwich (and entry level houses in Greenwich are $2MM+) or even Summit, that's more like Montclair. If you live in the San Fran area anwhere you'd be lucky to not spend 2x that on the house price alone. Just go on www.realtor.com and look at home prices and property taxes. $25k p.a. for kid's private school-that's more like kindergarten in a less expensive suburb. If you're in NYC, bump that to $40k for kindergarten, $50k+ for upper school. And that's just school: kids are actually a lot more expensive than that and it's all nickels and dimes but they add up. And forget about saving for college-lord knows what that expense will be in 13-18 years.
$55-60k in living expenses? I don't know what that includes, if you're counting a mortgage or not but let's leave a mortgage and property taxes out of the equation, that's $5k/month. You can easily eat up half of that just on utilities, food, gas and the other basics, not including two cars and insurance. That doesn't include anything "extravagant" like nice dinners out, which you will want to do because you work hard and your wife will want you to take her out because you work and travel a lot and you enjoy spending time together away from screaming children. Hell, a babysitter for 2 kids is $20/hour.
Go out for 4 hours once per week and a babysitter eats up more than 6% of your post tax budgeted living expenses. That doesn't include the $200 you blew on dinner and drinks or some other entertainment (that's in the burbs and not going over the top, not in NYC, Boston, SF, etc where you can easily blow 2x that) . And when you go out with friends you're no longer splitting the bill like you did when you were younger so you'll end up with a $400 tab far more than half the time because you work in a high paying job and people look to you to pay.
Regarding family vacations: a week long trip to Disney World for 4 will cost upwards of $10k with hotels, food and park tickets. That's not going to Bora Bora or Portofino on a private jet, that's Disney using miles for the flight. Before my wife and I had kids we'd travel for less (or more) but with a family it's really difficult to wing it and believe it or not, seeing my two young sons having the time of their lives at Disney was completely worth the money. Your second vacation of the year when you rent a modest house at the Jersey Shore (not meathead Shore), the Cape or the Vineyard for 2 weeks (and I'm leaving the Hamptons out of this) will cost you $10k in the rental alone. And you're going to get a place large enough for the grandparents and maybe other family members to come down and guess what? Because you're a consultant at Bain (or in IB/PE), no one will offer to pay you for anything: the rental cost, the thousands in food and drink you buy for everyone who's staying for free at your place, etc.
When you have a holiday dinner (Christmas, Thanksgiving) for your extended family and you spend >a thousand on food and booze, Aunt Mary will think it's all equal because she brought over the green bean casserole and guess what again? No one will offer to pay because you're the successful consultant, banker etc. I'm in no way bitter about this and I enjoy doing this for my family, but I'm just trying to illustrate how little things add up over the years.
You don't have to be chasing the Jones' or the Gates' to spend more than you think. For what I have made in PE and what I continue to make I live a pretty low key lifestyle but unless you want to be clipping coupons and skimping on everything possible, life in general will cost more than you think. If you can make consulting, IB/PE or big law partner type of money that you make in NYC, Boston, SF, etc and live in Des Moines, then it's a completely different picture but very few people make that type of money in Des Moines because those jobs don't exist in great numbers, if at all.
I only know one guy who retired at around 40. Formerly an MBB consultant who was recruited by a big hedge fund family because his industry specialty and his education were suited to the sub-fund's strategy. After a few years as an analyst he became a PM, and his direct fund ran something like $3B. Start doing your 2/20's on that amount of money and splitting the 20% with the firm (I think the team got to keep about half of the 20, maybe less but still a good % of it), making 20-30% annual returns and he took home a lot of money. Not just a million p.a. more like 10's of millions. And he lives a very moderate lifestyle for the money he's made because a massive house and fancy cars don't do it for him.
That's about the only way people who work in IB, PE, consulting or other high paying fields retire from what I've seen. Not when you have $3, $5 or $7MM, but when you have $30MM+. If you get to the point where you're ~40 and hitting the top of the game it means you've busted you butt since high school so it's very difficult to give it up when you're finally making the money you've worked most of your life to make. Plus, being 40 myself, I don't know what the hell I'd do if I retired in 3-6 years. There's only so much golf you can play and wine you can drink for a 30-40 year retirement.
If you're talking about retiring mid-50's I'd say that's more realistic. I applaud anyone who can save and not live an over the top lifestyle, but life in general will cost more than you think.
Mod Note (Andy): Throwback Thursday - this comment from April 2014 was originally posted in the thread What are exit opps really like for MBB Partners?