There is clearly something pervasive in society which makes people feel either that adults do not have problems, or that adults do not talk about their problems.
Needless to say, I do not agree with either of these opinions.
Everyone has problems, that's just the way the world is. Adults frequently cannot turn to parents in the same way that children did, and so if anything it's _more_ important to turn to other adults, talk about your problems, and get feedback from other adults, either with useful suggestions, or simple acknowledgement that your problem is a common one, and you are not alone in having it.
In addition, it seems that if people don't talk about the negative stuff that's going on then they get out of the habit of writing at all, and I don't get to see cool posts about the interesting/fun things they've been up to.*
Which leads nicely into the other point - the idea that your life is not interesting. Fundamentally, it's probably not, in a global sense. The chances of you being someone whose biography I would read if I'd never met you is pretty slim**. But if we have any connection (friends in meatspace, met you at a con a few times, enjoyed chatting online) then what you're up to _is_ of interest to me. I loathe the attitude I've seen from anti-Facebook/Twitter people of "Why do people think that their every movement is of interest to posterity?". Because posterity can go &$&^ itself, people's lives are of interest to their _friends_.
So if you have negative stuff in your life then feel free to share it, anyone that's not interested can unfriend you (or move you off their default view). And if you have nice, normal, stuff in your life then feel free to share it, and uninterested people can hit page down. And if you have awesomely cute kittens that you can photograph then feel free to share them, and frankly that's what the internet was designed for.
*Yes, it's all about me.
**Not least because I don't tend to read biographies.
Original post on Dreamwidth - there are comments there.