I don't think the ability to write goes away (unless you have a medical problem) but I do think it goes into hiding, especially if you don't do it.  I am finding that pushing myself to write, especially if I don't feel like it, helps and it doesn't matter what it is that I write.  I think we get caught up in having to write something we consider important, but maybe the habit is important to establish first and find significance afterwards.  One book I read said to write three pages first thing in the morning...write madly for three pages (not anything in particular, just do a download of thoughts) and then shut that notebook for the day.  It clears the cobwebs of the shouda, woulda, couldas, and may just put your brain in a writing mood.  I am finding that I am being more productive at work since I started doing that.  It gets all the venting, the anger, the frustration, the sadness out of the way for the day and lets me focus on the next project I have.  It's not a bad habit to get into...and one worth trying.