Is it normal to do anything at all?

I see a lot of posts on this forum asking questions like: "is it normal that I don't want to do anything?" or "is it normal that I'm not interested in anything?". Replies normally fall into three categories:

i) ask yourself why you are like this?;
ii) yes it's normal;
iii)no your a wierdo followed by some thinly disguised american dream selling dictum.

Want I find fascinating, however, is that these people must think that something is wrong with them, exactly because they don't want to do anything (I know I've thought this more than once). So I wonder if it's human nature to want to do anything at all, or is that just the message coming from somewhere, and we never think to question it?
I'd be interested to know your thoughts.