Best experience: My supervisor was upset to see me leave my internship this summer because I had become more competent with the program I was working with than anyone else in the company

Worst: It took 5 weeks of sitting and doing nothing to get to that point because the program was so broken and the creators of the program failed to allow any access or backdoor to make any changes, so we had to wait for them to get back to us about any and every problem. Even worse, they were based in Germany and never got back to us at a reasonable time...