Hi Cheese!
If I understand it right, it means smth like: for the person only one thing is important and this person doesn't care about other things (example: He may be poor, ugly, but I love him and nothing else matters).
Yes, this one is also a right interpretion. But in this case I thing we should say sth different like; "hiçbir şeyin önemi yok" or maybe the best one is; "gerisi boş" "