Knowing when to quit (or at least change gears)

First, welcome to rousell28 and zanazaz, the latest two followers to this blog.  I'm indulging in the rare "no pics" post for this blog because I've run into a pretty common problem.  Now and then I just start to really hate painting certain miniatures.  This usually blossoms out of resentment, which in turn comes from frustration.

Let me explain.  I have many Shock Troopers from Wargames Factory, which I intend to paint in a tan-and-green color scheme.  My problem is the dark green doesn't cover well over white, and tends to be really streaky and require many coats.  Like I said before, this gets frustrating which leads to resentment which leads to "why am I doing this?"

At this point, my best advice is to stop and switch gears.  It's a hobby, it is supposed to be fun, and if you're not shooting for having X number of points done in time for a tournament, you can come back when you're feeling more patient (or when you have purchased better paint).  I'm going to set the Troopers aside and paint some more zombies, which were fun and painted up pretty well, then take a look at the Chainmail miniatures I have on the Lead Pile.

I'm sure my somewhat philosophical turn here is partially composed by my impending birthday and subsequent mid-life crisis, but lately my hobby time has been more rare, and really thinking about what I want to do with it has become a more pressing issue.
Anyways, have a good Thanksgiving and I hope you get some time to enjoy yourself.