Apparently Mark Twain remarked that Wagner wrote music that was even better than it sounded! This is Twain's typical slightly convoluted use of words to make you think.
It made me think of resumes, which have to also be "better than they sound." The alternative, you see, is that they sound better than you are, which is not good in the end.
Being even better than you sound on paper, is much better than falling short of how you sound on paper. The first must be balanced, of course, so that your words sufficiently "tease" the reader with information that he or she wants to know about you, otherwise you won't land an interview. But overstating your abilities will ensure that you fall flat at the interview, moving your resume from fact to hype, and moving you from competitor to still-jobless.
When self-marketing, i.e. writing your resume and cover letter, stick to an elegant understatement of fact rather than an inflated, full of superlatives, "I'm the best thing since the internet," overdone document. Be memorable for the right reason!