I know that in E, if you don't beat Tabitha and Maxie at Mossdeep City, then there's an Aqua grunt preventing you from entering Seafloor Cavern. In DPPt, if you don't beat Cyrus at Celestic Town, then there will be some youngsters with Pokemon #025's and Clefairies that prevent you from entering Canalave City. So when you play through it again, you will try to not smash those rocks, right?