Table manners

Have you ever eaten in a foreign restaurant? Did you make any mistake? Please explain your experience. Did you learn anything?

I 've never eaten in a restaurant such as I need uncommon table manners. I know general table manners. For example, we put a knife and folk on a lower right of plate after eating. And my grandmother is a teacher of the tea ceremony, so she have strictly taught me manners.
When I was child, I can't use chopsticks well. My grandmother said me "You can't marry", and I practiced hard by her. I couldn't understand why I had to use chopsticks in restrictive way. But I thank her that she kept advising me. If I can't use chopsticks well even now, I would be ashamed of it. Table manners such as using chopsticks well are general intelligencce. And we need them because everyone have a meal comfortable together.