It is a sore point, because you do have advantages if you have access to more than one language. You also have problems, because on bad days you don't trust yourself, either in your first or your second language, and so you feel like a complete halfwit.

这是一个痛处，因为如果你能掌握一种以上的语言，你确实有优势。你也有问题，因为在糟糕的日子里，你不相信自己，无论是你的第一语言还是第二语言，所以你觉得自己完全是个傻瓜。