IIRC, I got a bit confused at that point as well. I may be misremembering this, but I think the issue is that the option to bang the pots shows up at the lake - but NOT the lake area with the fishing spot. Enter the forest, go to the left and pass the small log cabin. Then, at the screen where you have to turn left to reach the small bridge you had to repair, move forward instead and you should come to a small lake area.