The stock market at large has about a 4.5% long-term real-real (inflation-fees-etc-adjusted) rate of return. Yes: even in light of the recent crashes. That means your money invested in stocks doubles every 16 years. So savings when you're 25 and right out of college are worth double what savings are worth when you're 41, and four times what they're worth when you're 57.

You're probably going to be making more money when you're 41, but are you really going to be making two times as much? (In real terms?) And at 57, will you be making four times as much? And if you haven't been saving at all in your life, do you think you're going to be able to start, and make the sacrifices in your lifestyle that you may need? And will you save enough in 10 years to live for another 20-30 years after retirement? And what if the economy tanks (again) and your company goes under and you're out of a job when you turn 58?

Having tons of money at retirement isn't the only worthy goal you can pursue with your money (ask anyone who saves money to send kids to college), but having some money at retirement is a rather important goal, and you're much more at risk of saving too little than you are of saving too much. In the US, most retirement planners suggest 10-15% as a good savings rate. Coincidentally, the standard US 401(k) plan provides a tax-deferred vehicle for you to put away up to 15% of your income for retirement.

If you can save 15% from the age of 20-something onward, you probably will be at least as well-off when you retire as you are during the rest of your life. That means you can spend the rest on things which are meaningful to you. (Well, you should also keep around some cash in case of emergencies or sudden unemployment, and it's never a good idea to waste money, but your responsibilities to your future have at least been satisfied.)

James, money saved over the long term will typically beat inflation. There are many articles that discuss the advantage of starting young, and offer: A 21 year old who puts away $1000/yr for 10 years and stops depositing will be ahead of the 31 yr old who starts the $1000/yr deposit and continues through retirement. If any of us can get a message to our younger selves (time travel, anyone?) we would deliver two messages: Start out by living beneath your means, never take on credit card debt, and save at least 10%/yr as soon as you start working. I'd add, put half your raises to savings until your rate is 15%.

I can't comment on the pension companies. Here in the US, our accounts are somewhat guaranteed, not for value, but against theft. We invest in stocks and bonds, our funds are not mingled with the assets of the investment plan company.