> That sounds like if I was bombarded of pictures of people smiling drinking coke I might forget that it tastes like crap and want to drink it.

It certainly seems that you have made your opinion on coke, and that it's a strong one. Pictures of smiling people won't obviously overturn that, they don't have that large power, but in this case, you are not a target group.

However, imo majority of people don't have that strong opinon, and the less of that they have, the proportionally larger the weak influence of advertising will become.