Both are equally as important. It’s great to learn from your own mistakes because you suffer the consequence or thrive in the reward. But same for learning from others. If you are surrounded by people who are a bad influence, they may suffer the consequences of their actions and you will know not to make the same mistake they did. If you surround yourself with a good group of people, they may be rewarded for something they did or an achievement they reached, so it may encourage you to do better or be a better person like your friends.
Memory speaks to the world that has been lost, or all the more precisely the world that has been eradicated.
Either sentence A or B is correct, but I'm leaning towards B more than A. Hope this helps!
