This time I'm going to make your life better in a most delicious way (unless you are vegetarian/vegan). There's going to be some useful but gratuitous technical design stuff and some links, but the meat of the post is after that.
Importance of simplicity
KISS. Keep it simple,silly.
But why? Because people don't like to learn and won't bother to when they can avoid it: http://www.nngroup.com/articles/stagnating-expertise/ If you force cognitive strain on your users you will lose their trust and this has many downsides: http://www.nngroup.com/articles/navigation-cognitive-strain/.
When we look at great designers who have done simple well, it's hard not to see Steve Jobs at the head of that group (these quotes are from http://blogs.wsj.com/digits/2011/08/24/steve-jobss-best-quotes/, which includes many others if you like this sort of thing):
“Simple can be harder than complex: You have to work hard to get your thinking clean to make it simple. But it’s worth it in the end because once you get there, you can move mountains.”
“Look at the design of a lot of consumer products — they’re really complicated surfaces. We tried to make something much more holistic and simple. When you first start off trying to solve a problem, the first solutions you come up with are very complex, and most people stop there. But if you keep going, and live with the problem and peel more layers of the onion off, you can often times arrive at some very elegant and simple solutions. Most people just don’t put in the time or energy to get there. We believe that customers are smart, and want objects which are well thought through.”
Simplicity tells your audience that you care. Even if they are smart enough to use your complicated product and even if they are inclined to do so, they won't forget that you didn't try harder to build them what you should have.
If you are jonesing for some more technical discussion of why simplicity matters in software design, here's Rich Hickey's 2012 Rails Conf keynote: http://www.youtube.com/watch?v=rI8tNMsozo0. Some folks prefer his talk from Strange Loop the year before: http://www.infoq.com/presentations/Simple-Made-Easy Either way, you win.
Winner, winner, chicken dinner
We cook at home often. After a while, we got good enough that the results were better than going out in just about every way (except the cleaning up part afterwards). This of course leads to experimentation, different styles of cooking, using different approaches, etc. Some times these can get quite involved and use small amounts of difficult to find or expensive ingredients (and you always need to find the recipe to recreate it).
This post is a result of a recent chicken dinner at home. Everything I wrote above was just to get us here. I was surprised that such a simple recipe regularly produced some of the most delicious chicken I'd ever enjoyed. But as I pondered that, I realized that the simplicity may be the reason it was so reliably good.
Having prepared chicken many ways over the decades, we've settled on this recipe: http://www.epicurious.com/recipes/food/views/My-Favorite-Simple-Roast-Chicken-231348 because it is simple, easy to follow and yields the same delicious result every time. It's literally as simple as (1) rinse and dry the bird, (2) salt and season the cavity, (3) truss the bird, (4) rain salt on the outside, (5) cook it for about an hour. Sit down to a delicious dinner -- if that sounds too easy, just try it.. If the trussing-the-chicken part has you worried, it's also dead simple -- here's a 90 second video that will have you doing it in no time: http://ruhlman.com/2010/07/how-to-truss-a-chicken/
Simplicity isn't just about the quality of the result but also in how you get there. Thomas Keller is a phenomenal chef and could have written pages worth of directions (that people would have slavishly followed), but they weren't needed. He had a simpler way that worked perfectly every time. After you have done this once, maybe twice, you won't even need the recipe any more -- the simple steps will just stick in your brain. That's perfect instructional design. Enjoy!
Addendum: "Winner, winner chicken dinner" was stuck in my mind and I couldn't remember where it came from. So I had to Google it: http://www.urbandictionary.com/define.php?term=Winner+Winner+Chicken+Dinner