That it is almost obvious that it's either the work of an anon troll or someone who just made an account. You either don't bother answering or give some smart ass response. Then get to thinking, "maybe it's real" and feel bad?
I usually just skip over them, unless I'm in a fun mood, then I'll give my usual smart ass reply. Then, I always wonder if it was really a troll or if someone really needed advice. And I feel bad. :-(