good for nothing
A phrase that can describe two entirely-opposite ends of the meaning-spectrum, depending on how the words are punctuated.
Example:
A "good-for-nothing" is, of course, someone who lacks the knowledge and/or motivation to make himself useful in any way. But on the other hand, someone who zealously toils and struggles his a** off trying to totally "be a saint 24/7" but receives no better treatment as a result of it --- in other words, his fellow humans mistreat him with just as much chilliness and lack of charity as if he were just a "good-for-nothing" --- will feel as if he's been "good for nothing"... he's totally worn himself out trying to be "Honest Abe" and "Sir Galahad", yet nobody acknowledges or appreciates his efforts, and so he's behaved himself exceptionally but received zero reward or praise for his efforts.
A "good-for-nothing" is, of course, someone who lacks the knowledge and/or motivation to make himself useful in any way. But on the other hand, someone who zealously toils and struggles his a** off trying to totally "be a saint 24/7" but receives no better treatment as a result of it --- in other words, his fellow humans mistreat him with just as much chilliness and lack of charity as if he were just a "good-for-nothing" --- will feel as if he's been "good for nothing"... he's totally worn himself out trying to be "Honest Abe" and "Sir Galahad", yet nobody acknowledges or appreciates his efforts, and so he's behaved himself exceptionally but received zero reward or praise for his efforts.