I know a lot of people on this board are younger, so as an older guy and a parent I feel compelled to comment.
Please, read this article:
http://www.mrmoneymustache.com/2012/01/13/the-shockingly-simple-math-behind-early-retirement/
You can quibble a bit with the math, but the sentiment is dead-on.
If you save two-thirds of your income, you can work for 10 years and retire. If you save 50% of your income, you can work until you are about 40 and retire. If you can save 33% of your income, you can work until you are about 50 and retire.
That is clear math. So, say you want to retire at 50. Never let your expenses get higher than 67% of your income and put 33% away. You'll be able to retire at about 50 and keep the same lifestyle until you die.
Yes, you have to have your expenses totally in check, not get into debt, and invest wisely in index funds. Things that 90% of people seem to not be able to do. But it isn't that hard.
I can tell you that I am in my early 50's and have invested at least 30% of my income each year, lived well but always below my means, and I am in a position when I can retire whenever I choose to.
Yes, it helps if you have a higher income, but I'd say for any college graduate who can earn a decent living, there is no reason to ever have financial problems as long as you have a bit of discipline with your money.