It's classic for the engineering mind set to view all things that are easy as unimportant, and all things that are unimportant as easy. Both are good rules of thumb, but neither is strictly true.
That is so wrong though I believe that many people make that assumption.
As for "trivial" I agree that unimportant, uninteresting, insignificant or even self-evident or obvious are better definitions than 'easy' even though a trivial solution may be an 'easy' one.
Those are also words to use carefully around clients since they often associate 'easy' or 'trivial' with low cost. Just because something is "easy" for me doesn't mean it's low cost for you.
