If you know anything at all about personal finance you know about the power of compound interest. When you're young this is a huge advantage that means saving a little bit now will pay off big time later. But for various reasons many of us don't even save that little bit.
I contribute $20 a paycheck to my work 401k. Yes, just $20.
That may sound ridiculously small, and you may feel embarrassed emailing your HR person to tell them to put so little in your account. But get over yourself and just do it. Anyone can afford $20 out of each paycheck, and it's true that when its automatically taken out you don't miss it one bit. I contribute so little to my work 401k because I don't get a match and so I focus on a Roth IRA for my retirement savings. For someone older I might spreading themselves so thin would be a waste of money, but when you're in your 20s it is very wise to put something, anything in an account and give it time to grow. Hopefully I will someday be in a financial situation where I will be making too much to fund a roth, or where my employer offers a match to my 401k, and at that time I will be very glad that I had started a fund to grow from.