It's only when you've written such things that you really understand them,with insight into when they are and aren't use
问题描述：
It's only when you've written such things that you really understand them,with insight into when they are and aren't useful,what the efficiency issues are,and so forth.
答
只有当你写下这些东西你才能了解它们是否有用,有效的要点是什么.