"Everything is permissible"—but not everything is beneficial. "Everything is permissible"—but not everything is constructive.
My "poor man's version" of this passage is "Just because you CAN do something doesn't mean you SHOULD do it." I know there is a lot more to this passage and that I am pulling it out all by itself, but I think it's a good "life saying". Basically, use your common sense and THINK before you act. That's a tough one for me.