More often than not, inability to put anything aside for retirement is a priorities issue, and not a true income issue.
I see plenty of people with the latest Samsung or Apple smart phone, cable TV (with premium channels, gotta have game of thrones), Netflix, a new or newer car with a nice payment, living in a 2 bedroom apartment as a single person with no kids, eating out for lunch most days at work, and i could go on...
Anyway, I don't know how many times I've heard those guys talking about not having any money to put back for retirement.
It's prioroties.
They have made a conscious decision that several luxuries are more important to them than putting back a couple hundred , or even one hundred bucks a month back.
Shit I started at 17 putting $25/month back.
Anything, at a young age, is better than nothing.