Yeh, I had file 1 as my first play through, finished it and kept it as last save so i could side-quest etc. and started another as File 2 which went on to become Second Quest. 1 year later, i started File 3 just for fun.
I managed to get 20 hearts in my first 2 files, but couldn't be bothered in the third. The only thing I need to do in File 1 is complete Nintendo gallery, which I never really got into.