It's just a job. Grass grows, birds fly, waves pound the sand. I beat people up.

Ali’s line uses a deliberately plain, almost comic comparison—natural processes (grass growing, birds flying, waves pounding sand) set beside his own work—to normalize the violence of boxing as routine labor rather than moral drama. The blunt final clause (“I beat people up”) strips away glamour and rhetoric, suggesting a professional’s detachment: he is paid to do a specialized, physical task, not to embody brutality for its own sake. At the same time, the phrasing plays with Ali’s public persona: the understatement reads as self-aware performance, turning a potentially troubling truth about prizefighting into a memorable, quotable bit of candor.