YOU SAID:
why did I think that would work?
INTO JAPANESE
なぜそれがうまくいくと思ったのですか?
BACK INTO ENGLISH
Why did you think it would work?
INTO JAPANESE
なぜそれがうまくいくと思いましたか?
BACK INTO ENGLISH
Why did you think it would work?
That didn't even make that much sense in English.