YOU SAID:

can a can cram another can into a smaller can if it tells itself it can because it believes it can

INTO JAPANESE

缶はそれができると信じているのでそれができるとそれ自身に言うならば、別の缶をより小さな缶に詰め込むことができます

BACK INTO ENGLISH

If you tell yourself that a can can do it because you believe it can, you can pack another can into a smaller can

INTO JAPANESE

あなたがそれができると信じているので缶がそれをすることができるとあなた自身に言うならば、あなたは別の缶をより小さな缶に詰めることができます

BACK INTO ENGLISH

If you tell yourself that a can can do it because you believe it can, you can pack another can into a smaller can