My Faroese friend told me about World War II on the Faroe Islands.
A lot of British soldiers were stationed there, and got quite popular by behaving nicely and exchanging chocolate for lighters. They were so well liked the Faroese people often gave them food for free and invited them to dances.
The Norwegian soldiers however made themselves unpopular by behaving less polite and taking lighters without giving anything in return.
To this day some of the older generation on the islands still dislike Norwegians for this chocolate betrayal.
So remember, never not give people chocolate! They remember that stuff!