Said of something that is a positive occurrence (especially when it initially seems bad or problematic). This is usually an expression of hope or insight after something has gone awry. I had to go home and change after spilling coffee on myself, but it was all for the best because I avoided a major traffic jam. I was really disappointed to get rejected from my first-choice school, but I think it will be all for the best because now I won't be so far from home.