Accumulate s a kind of thinking method which lurks at the base of our "play" spirit. When we experience something even if it doesn’t go well, these experiences accumulates inside of us, so it will be an opportunity to increase the success rate of the next work. As you guess, it’s fun when our work goes well, but you need to remember your failed trials. Exam is a good example for this claim. When you learn and correct your mistake, you can get extra points. It’s the same with this. If you learn from your mistakes, your success rate will increase. If you cannot accumulate these experiences and act recklessly, there is a possibility that things might go wrong. Knowledge and technique are like this. Mathematics is a good example here. You need to be perfect with the basic knowledge of math, if not you can’t get any better in math. If you don’t have these kind of habits and only rely on verbal memory, even if you do succeed time to time, you can’t succeed. Thus accumulation idea would collapse. Those who went over the basics can’t improve themselves easily. In business world, it’s better to train the basics of computers repeatedly.