We all need to face this fact, guys--no matter how young or old you are and no matter how much or how little there is in your take-home, 10% of it does not belong to you. That portion belongs to the retired you. This takes some painful belt tightening, It may mean driving an older car or no car. It may mean rooming with somebody or staying with parents instead of having your own place. It may mean relying on a partner or parent for some of life's essentials, if that person is able to help and wants to help.
There is no reason to fear market volatility. Just take that 10% and invest it as soon as you receive it. This is called dollar cost averaging. If the market is up, yay for you. If the market is down, your money is buying more shares because they cost less. You win either way. A diversified mutual fund, such as a fund that is indexed to the Standard & Poors 500, is a safe long-term bet. This index includes 500 of the largest publically-held companies in America.
Do this in a tax-defered account. If your employer offers a 401K, do it that way. If not, open an IRA. Don't count on this money for rainy-day emergencies because, with a few exceptions, you won't be able to get it back out before retirement unless you are willing to pay huge penalties.
If you don't understand some of this, take one of those short adult-ed investing classes at a local community college. Print out this message and take it with you when you go.
I did all this. It's not impossible, even if you find yourself eating Ramen noodles, which I did plently of times. At 61 I am more than grateful to the young me--it turns out he was a pretty generous and selfless guy!