It's a mistake.
這是個錯誤

Okay,yes,it's a mistake.
好吧，對，這是個錯誤

I know it's a mistake.
我知道這是個錯誤

But there are certain things in life
但生活中有些事情

where you know it's a mistake
你知道會是錯誤

but you don't really know it's a mistake
卻又不明確一定是錯誤

because the only way to really know it's a mistake is to make the mistake,
因為明確這是一個錯誤的唯一方法，就是犯下這個錯誤

and look back,and say,
然后再回頭看，就可以說

"yep.That was a mistake."
"對，是個錯誤"

So,really,the bigger mistake would be to not make the mistake,
所以，不犯這個錯誤將是個更大的錯誤

because then you go your whole life not really knowing
因為這樣你一輩子都不能肯定

if something is a mistake or not.
這是不是錯誤

HIMYM追愛總動員 - Lily莉莉