On Mario and Luigi Bowser's Inside Story, is Backtracking Possible?

I recently got through the Flab Zone, and realized I forgot one of those (pardon me, I can't remember what he're actually called) skill puzzle pieces (ya know the ones... Collect 10 and learn a new skill?) When I went back to the Flab Zone, the layout was different and I couldn't get back up there... Am I gonna be able to get that last puzzle piece or should I reset the game?On Mario and Luigi Bowser's Inside Story, is Backtracking Possible?
The other answer is incorrect. You will indeed be able to re-enter the flab zone and get the other skill points. It happens later on when Bowser can do his jump move. He will go to his castle and eventually make it back to the room with the junk food. From there you can make him eat as much as you want and then switch to Mario/Luigi and enter the flab zone again to get the pieces.On Mario and Luigi Bowser's Inside Story, is Backtracking Possible?
u have to restart. sorry.