YOU SAID:
Never have I ever seen a hat as dumb as that.
INTO JAPANESE
決して私は今までそのような愚かな帽子を見てきました。
BACK INTO ENGLISH
Never I've ever seen such a stupid hat.
INTO JAPANESE
決して私は今までこのような愚かな帽子を見てきました。
That didn't even make that much sense in English.