What do you think of these categories? This is one of major topics that people are concerned about.
Health is about losing weight, changes of your appearance, diseases, aging, fertility.
Ambition is about future dream, job, promotion, lay-off.
Relationship is about the relationship with friends, relatives, kids, girl/boyfriend, marriage, divorce.
Money is about your income, debt, loan, 401k, investment, pension, real estate.
Any other categories?
Along with them, multiplying the age factor, we might be able to guess more accurately what would be the typical issues for a certain group of people.
For example, if it is about teenagers x health, they are concern about appearances like weight, height, skins. For 20s, they might get stressed out and have backache or stiff shoulder. 30s women might be more serious about having a baby if she wants, and men consider decreased stamina or muscles, more weight. As for 40s, people might be more interested in cancer insurance. After 50s, more bigger portion of their concerns are occupied by health related issues.
The above categories and factored by age was found in one of the book I read. We cannot apply this classification of issues based on generation to single individual. However, it could be good start if you are thinking of concerns for a certain group of people.