Wuppo

You can get this achievement at the Fortune Teller in Wondersplenk, which is an amusement park.

Wondersplenk is first availble when you get to the Train Station after getting the PoPo Chipcard. Jump above the Info Guy by the train timetable and instead of going down the stars marked "Popo" go above (the sign says Splenk). Keep going left untill you get to Wondersplenk.

Once in Wondersplenk you need to buy some Wondersplenk coins fromt he first guy in the little tent (almost underneath the Megakrank sign). I bought 50 but I think you only need 30 for this and its 9 smurt for 1 wondersplenk coin.

The Fortune Teller to the left and down, jump down the gap where the "Joysplenk" sign is pointing. The cery short steps lead left then right and once on the floor the Fortune Teller is bottom left. It's dark here so for clarity its to the left of the sign saying "Record" wth a number underneath it.

Once in the Fortune Tellers ilsten to her fortunes again and again. Like I said, it's about 30 times. You do get some happiness with some of the fortunes but after a decent amount of fortunes she'll confess to being a fraud and you'll get dialogue options. I picked "I knew the whole time" and "Your funny" and at the end of the conversation the achievement popped.