A fateful day, choice, or meeting is one that changes what comes after — and the change is usually heavy or bad. After it, life is not the same. The word does not mean full of magic. It means this was the turning point. News writers like it because it makes a moment sound important: a fateful decision, a fateful night. Though actually, people sometimes stick fateful on a story just to add drama, even when nothing terrible followed. In careful talk, keep that shadow of trouble. It is a little formal; with friends you might just say that was the day everything went wrong.