True expertise is revealed when faced with the most difficult problems. If we simply move the obstacles neatly to the side, ignoring them, can we truly call ourselves professionals, or experts at anything?

I like to see constraints (old browsers, small screen sizes, progressive enhancement, accessibility considerations, you name it) as challenges. If I can make something work without avoiding them, I will be prouder about my work and will have learned a whole deal more than if I just chuck them aside.