It's unlikely you could ever save enough using low-return guaranteed- or fixed-income assets to meet your retirement needs. You simply have to invest in enough risky assets to get the total return necessary to fund your retirement nest egg. But with uncertainty today about global markets, high volatility and a fresh memory of a near global financial meltdown, far too many investors have been fleeing the stock markets. That's a huge mistake. After every "crisis" global markets have always recovered, and this time it's no different.

When you think of it, stocks are a lot like tuna fish. You buy them today to use sometime in the future. You don't expect to eat tuna in the store, and probably not even when you get it home that day.

If you're scared about buying lower-priced stocks for your retirement portfolio, well, just imagine you're stocking up on tuna fish.

Let's pretend you, your family and your cat eat a fair amount of tuna fish. As you know, it comes in cans and has a long shelf life. We are used to buying it in large cans for $1.50. Now one day we go to the market and see that it is on sale for $1 a can.

What do we do?

Do we see ourselves as impoverished because we already have some cans back home on the shelf?

Do we run home, grab all our unused tuna fish and run back to the store to sell it back?

Do we feel bad because we have lost money on our cans at home?

Do we run home and throw them all out?

Do we vow never to buy tuna fish again?

Do we organize a protest march?

Do we start a campaign in the newspaper, on our Facebook page or on Twitter?

Of course not! We buy lots of tuna fish to take advantage of the low price. We know that we will need tuna fish for a long time and that the sale offers us a great opportunity to stock up for future needs. We have made the mental jump that low price = good.

Stocks have a long shelf life too, and we buy them to use them a long time in the future. If you are a 401(k) participant, the stocks you buy now will be there when you need them in retirement. But the average investor seems to operate on the assumption that low price = bad! Rather than seeing temporary low price as an opportunity to buy something needed in the future, he wants to dump what he has.

Especially if you have a few years to go before retirement, you should be dancing in the streets. This is your chance to scoop up bargains at very attractive prices. The world markets are on sale. Buy them while they're hot!