I am not stupid and I have learned that the most annoying way to check out is at the self check out. If something is going to go wrong or be incorrectly priced it will happen when at the self checkout and then getting help only makes you look like an idiot. I refuse to use them and when prompted my the teenage clerk that the self checkout lane is open I just ignore them.
AFAIC, the self checkout is the door. There is no way in hell I'm going to ring up my stuff and pay for it. Blasphemy!