There are lots of physicians out there making $400K per year who are just scraping by. I know several. The problem, however, has nothing to do with their income but rather their spending habits. Just like it is possible for someone who makes $60K to buy too much home and too much car and too much vacation, it is possible for someone who makes $400K.
Even docs benefit from being frugal. Also, keep in mind that as your income climbs, a much larger percentage goes to stuff that the less fortunate don't pay. I make less than $150K, but after retirement plan funding, charitable contributions, and taxes (especially self-employment tax) I only take home $56 of my $150/hour moonlighting gig salary.
It's a nice problem to have, but don't get into the mindset that someone who makes $400K can live 8 times as well as someone who makes $50K. They can live 3 times as well, sure, but not 8 times.
The wise physician never lets his spending level get anywhere near his income. You've got too much to make up for (remember how you didn't put anything into your 401K during your 20s and buy a house when you were 25 like all your friends did? Now's the time to make up for that with a higher savings rate.)
Plan on paying 1/3 in taxes, saving 1/3, and living off 1/3 and that'll be about right.