Lots of laughs and whatnot, until you reach 30 something and realize you should have taken care of yourself a whole lot better!
I would venture a guess that almost 60-70% of everyone who replied here will see a doctor in the near future about this exact same problem. Drugs, alcohol, stress, unfit, lifestyle.
Has nothing to do with being 30 - I was 24 at the time...but it will most probably affect the majortity of men at least once in their lives.