Most people who have never been to Japan but are interested in Japanese culture and cuisine believe the litmus test for tolerating said cuisine weirdness is an enjoyment of sushi, or perhaps, sashimi. If you can stomach raw fish, you may believe you earned your member's badge. If you've actually lived here, you know that adoring sushi is something only lightweights regard as an accomplishment. The real question, and Japanese people love to ask it, is "can you eat natto?" Natto is a slimy, sticky fermented soybean concoction that smells like gym socks that have been left to ripen in a dark, dank locker for a century and has the texture of something you'd spit up when you had a bad chest cold. It's disgusting, and there are many Japanese people who eat it for breakfast everyday. It's very healthy, mind you, but that doesn't stop it from being an acquired taste that you're likely to only acquire if you grew up with it or were forced to choose between starvation and this foodstuff. From a country in which some people say that mozzarella cheese is too stringy and that is what keeps them away from pizza, it is quite ironic that they think natto is the bee's knees.
I won't miss the knowing smirks, smug grins, and superior attitude I get when I answer the question, "do you eat natto," with "no."