世界不一定要这样。事情可以不同。

I do not know what I may appear to the world， but to myself I seem to have been only like a boy playing on the sea-shore， and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary， whilst the great ocean of truth lay all undiscovered before me.

解释：不可以不知道活着的乐趣，也不可以不知道虚度光阴的担忧。