"Anyone can build a bridge. It takes an engineer to barely build a bridge."

I heard this on a train, I've never been able to find the source, and I use it to explain the difference between solving a problem and elegantly solving a problem. Another perspective (attributed to R. Buckminster Fuller but I'm not confident about that attribution):

"When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong."