Immaturity is the disease resulting in the 'quarter-life crisis' and 'mid-life crisis' phenomena. Personal responsibility is the cure.
More young people today are raised in such a manner that they lack a solid sense of personal responsibility. Some develop personal responsibility when confronted with their first really stressful situation after they are out on their own. Some never develop it. The ones who don't develop it are most likely the ones giving it a name like 'quarter-life crisis'. Just the name sounds like they are trying to treat it like something that 'happened to them'.
There are a myriad of contributing factors and symptoms.
The trend has been that more and more parents are paying for more and more of their teenage children's spending habits. Cell phones, car payments, insurance, gas, and more. Allowances are out of hand. When teenagers have "sugar parents" that cater their every desire and do not see the value in making them work for what they want, personal responsibility does not develop properly, if at all.
The 'quarter-life crisis' certainly could be one of the symptoms. Financial responsibility is on the decline. That is one reason why the US has a negative savings rate. At a time when pensions are going away and self-directed retirement programs like 401k's are on the rise, many young people are used to not having to think about the future so they do not contribute. It is a growing trend that adult children are still living with their parents, even after they are out of school.
Emotionally, many of these children may have never had to really look themselves in the mirror and discover what they want to do with their lives. Why even bother doing so until you know in your gut that you are going to have to support yourself and can't fall back on your parents for support? As long as they perceive a safety net, they will not go through the process of developing the confidence and emotional fortitude required to go out into the world on their own merit.
More and more parents need to realize they are enabling their children to fail in life. There is a lot of the "she's only a child once, let her have some fun" rhetoric going on. We all would do well to remember that a parent's job is to provide a loving environment for their children in which they can prepare for a successful life. A life 'crisis' happens when someone realizes they have been missing out on something. They respond by either getting with it, or avoiding the problem by spending money they don't have or making some other drastic change in search of a different way.
I had a 'crisis' about a year ago when I was 28. I realized that I had been stupid financially for all my life up until that point. Instead of avoiding the problem, my wife and I confronted it head-on. We admitted we had been stupid, devised a plan, and are now following it. We've paid off $20,116 in debt in one year on a $42,000 combined gross income. Instead of letting our financial life 'happen to us', we turned that situation on its head. We are now driving our financial lives.