難し

彼（かれ）、能書（のうが）きばかり立派（りっぱ）だけど、言（い）うは易（やさ）く行（おこな）うは難（むずか）し、ってこと分（わ）かってんのかなあ。

His boosterism makes it sound wonderful but I wonder if he understands how hard it's going to be to actually carry out.