Behavior can help — get an education, work hard, spend less than you make, save money, etc.
But, really, there is a limit to what behavior can do. The demographics indicate that as Baby Boomers retire (something well underway) there will simply not be sufficient numbers of people working, producing, consuming, and paying taxes. Our economic system (and this is true around the world) has been built on the idea of lots and lots of productive people pushing economies into overdrive. That’s over. There aren’t enough young people. It’s not a fixable problem in any real sense.
The good times are over.
If there are fewer workers, you would expect wages to be relatively higher, and the returns on the investment that retirees are holding to be relatively lower. But the demographics aren’t that bad - there are more millennials than Baby Boomers.