YOU SAID:
I had something, but I forgot it now, because that happened.
INTO JAPANESE
私は行くつもりだったが忘れた。
BACK INTO ENGLISH
I intended to go, but forgot to.
INTO JAPANESE
私は行くつもりだったが忘れた。
BACK INTO ENGLISH
I intended to go, but forgot to.
That didn't even make that much sense in English.