You aren't Wrong

There was a time when a pupil shought his master angrily, it seemed that the student just experienced a very bad oment.

Student: Master you did say that one must not think twice when a chance come in front of our eyes, didn't you?

Master: Yes, indeed I said it clearly to you.

Student: So whats wrong with me, so I get this stupid luck when I do what you've told me?t

Master: No my child, you aren't wrong at all. But I didn't mention not to think at all as well, didn't I?

Ah..., then the pupil leave his master when a red face...